Matsushita Electric Industrial Co., Ltd.

Tatsuaki Ishida

Kiyokazu Tohma

Ryuji Sugita

Keizo Miyata

Yasuaki Ban

Taizou Hamada

Hideyuki Hashi

Kazunari Yoshimoto

Hiroshi Ryonai

Keizou Miyata

Nobuyuki Komura

Kazuyoshi Honda

Yasuhiro Kawawake

Kiyokazu Thoma

Noriyasu Echigo

Toshio Makabe

Hiroyuki Hasegawa

Yoshiki Goto

Taizo Hamada

Kiyokazu Toma

Yukihiro Shimasaki

Kaoru Matsuoka

Hiromi Kita

Yoshio Umeda

Hiroshi Kohso

Ryosuke Shimizu

Yoriko Takai

Terumi Yanagi

Kouji Taniguchi

Makoto Kimura

Syuichi Yoshida

A self-servo reference signal including a timing pattern and an oblique phase pattern is transferred in advance on a magnetic diskby magnetic printing. A phase difference detection sectiondetects a phase difference between the two patterns to detect the position of a magnetic head. A burst signal generated by a record signal generation sectionis recorded in a region of the magnetic diskwhere no self-servo reference signal is recorded. A track pitch calculation sectiondetermines a relationship between the reproduction output of the burst signal detected by a reproduction signal processing sectionand the phase difference detected by the phase difference detection section, thus calculating an optimum data track pitch.

Magnetic disk apparatus, method for determining data track pitch, and self-servo write method

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 magnetic transfer method which superposes on a magnetic disk surface a magnetic transfer master disk () on which a magnetic film is formed so as to have an array pattern shape corresponding to a preset information signal, and magnetizes the magnetic film on the master disk () to thereby magnetic-transfer-record the array pattern of the information signal on the master disk () onto the magnetic disk as the magnetized pattern of the information signal, the method characterized by comprising a step of contacting/separating to/from a dummy disk () the magnetic film-formed surface of the master disk () to thereby clean the master disk (), and a step of superposing, after the cleaning, the master disk () on the magnetic disk for magnetic transfer recording; and a magnetic transfer device for the method.

Magnetic transfer method and magnetic transfer device

A master information carrier includes a high-level region and a low-level region that are formed on a non-magnetic base. The high-level region includes a ferromagnetic thin film pattern that corresponds to preformat information signals. The master information carrier is brought into close contact with a magnetic disk by exhausting a gas from a hole of the magnetic disk to generate negative pressure in a space between the low-level region and the magnetic disk. In this case, to prevent deformation of the central portion of the master information carrier, an inner edge of the high-level region in the radial direction is extended to the vicinity of a hole edge of the magnetic disk so that a portion of the high-level region comes into contact with the vicinity of the hole edge. This configuration can improve the close contact between the master information carrier and the magnetic disk, thus achieving higher reliability of magnetic transfer recording.

Master information carrier and method for manufacturing magnetic disk

A master information carrier comprises a substrate whose surface has an embossed pattern corresponding to an information signal. At least a surface of the protruding portion of the embossed pattern is made of a ferromagnetic material. A method for writing an information signal into a sheet or disk magnetic record medium with a ferromagnetic thin film or coating is performed by putting the surface of the magnetic record medium into contact with the master information carrier so as to write a magnetized pattern corresponding to the embossed pattern of the master information carrier into the magnetic record medium.

Master information carrier, method for producing the carrier, method and apparatus for writing information into magnetic record medium using the carrier

In a manufacturing method for a magnetic recording medium, when the length of a ferromagnetic thin film on a master information carrier corresponding to the length between a pair of magnetization transition regions adjacent to each other is A in magnetization information recorded onto a magnetic recording medium, the film thickness of the ferromagnetic thin film is t and A/t is k, k is set from not less than 0.8 to not more than 8.

Manufacturing method for magnetic recording medium, and master information carrier used therefor

A magnetic transfer method includes a first step (ST) of preparing a magnetic disk, a second step (ST) of forming a layer of lubricant on the magnetic disk, a third step (ST) of bringing a surface of the magnetic layer on the magnetic disk into close contact with a magnetic transfer master having a magnetic film formed on at least one side and magnetically transferring a pattern of the magnetic film on the magnetic transfer master onto the surface of the magnetic disk through application of an external magnetic field, and a fourth step (ST, ST) of burnishing at least a surface of the magnetic disk that comes into contact with the magnetic transfer master. The first step, the fourth step, the second step, the fourth step, and the third step are performed in the stated order.

Magnetic transfer method and magnetic transfer apparatus

A magnetic transfer method includes a first step (ST) of preparing a magnetic disk, a second step (ST) of forming a layer of lubricant on the magnetic disk, a third step (ST) of bringing a surface of the magnetic layer on the magnetic disk into close contact with a magnetic transfer master having a magnetic film formed on at least one side and magnetically transferring a pattern of the magnetic film on the magnetic transfer master onto the surface of the magnetic disk through application of an external magnetic field, and a fourth step (STST) of burnishing at least a surface of the magnetic disk that comes into contact with the magnetic transfer master. The first step, the fourth step, the second step, the fourth step, and the third step are performed in the stated order.

Method and apparatus for magnetic printing

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 master information carrier with excellent durability is provided, for the use of static and a real lump-sum recording of digital information signals on magnetic recording medium. The master information carrier comprises a non-magnetic substrate on which a ferromagnetic film is disposed with an embossed pattern. Protrusions of the embossed pattern correspond to a disposition of the digital information signals. Recessed portions of the embossed pattern of the ferromagnetic film are filled with non-magnetic solid material. Alternately, A non-magnetic substrate has an embossed pattern and recessed portions of the embossed pattern correspond to a disposition of the digital information signals. A ferromagnetic film is filled in the recessed portions of the embossed pattern.

Master information support

Instead of directly performing defect inspection using a master information carrier, an inspection substrate is prepared to then bring the master information carrier in close contact therewith, to thereby transfer a defect on the master information carrier to the inspection substrate, thus indirectly inspecting any defect of the master information carrier on the inspection substrate. Defect inspection is performed on the first-state inspection substrate before close contacting, so that a defect inspection result on the second-state inspection substrate after close contacting and that on the first-state inspection substrate are compared to each other.

Master information carrier/magnetic recording medium defect inspection method

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 magnetic transcription device for transcribing information signals of a master information carrier in a magnetic recording medium by applying a magnetic field generated by magnetic field generating means to a contact body obtained by contacting the master information carrier having a base on which ferromagnetic bodies corresponding to the information signals are formed with a magnetic recording medium having a ferromagnetic layer, wherein the magnetic recording medium includes driving means for adjusting a distance between the magnetic field generating means and the contact body while rotating the magnetic field generating means relative to the contact body. Accordingly, an external magnetic field can be applied and removed for transcription of the information signals of the master information carrier in the magnetic recording medium while rotating the magnetic field generating means relative to the contact body, so that the deterioration of reproduction signals from the magnetic recording medium can be prevented.

Magnetic transcription device

A high-level region and a low-level region are formed on a surface of a nonmagnetic base member, in which high-level region is formed a ferromagnetic thin film pattern which corresponds to a preformat information signal, in such a structure that a flow promoting shape of such a shape (e.g., smooth curved shape, polygonal shape) that inhibits the stagnation of a flow of a detergent to promote the flow in order to prevents sticking and residing of foreign matter contained in the detergent is formed at an area where the detergent is liable to stagnate in the high-level region, i.e. at an inner radial portion of a disk-shaped mater information carrier.

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Shiga, Japan

Tatsuaki Ishida