Matsushita Electric Industrial Co., Ltd.

Kiyokazu Tohma

Tatsuaki Ishida

Ryuji Sugita

Hiroshi Ryonai

Kazunari Yoshimoto

Keizou Miyata

Taizou Hamada

Yasuaki Ban

Kazuyoshi Honda

Keizo Miyata

Hideyuki Hashi

Yasuhiro Kawawake

Nobuyuki Komura

Yoshiki Goto

Yukihiro Shimasaki

Yoshio Umeda

Ryosuke Shimizu

Yoriko Takai

Yoshiki Murakami

Yasuihiro Kawawake

Taro Nanbu

Syuichi Yoshida

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

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

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 master-information magnetic recording apparatus for recording preformat information signals into a magnetic recording medium using a ferromagnetic film pattern formed on a master information carrier, in which the pattern corresponds to the preformat information signals. With the master information carrier in contact with the magnetic recording medium, the ferromagnetic film pattern is magnetized by a magnetic field applying device. Thus, the preformat information signals are recorded into the magnetic recording medium. The magnetic field applying device is so constructed that the direction of magnetizing the ferromagnetic film pattern is perpendicular to a track-scanning orbit of a magnetic head in a recording and reproducing apparatus in which the magnetic recording medium is installed. It enables the magnetic head to gain sufficient reproduction amplitude for track-scanning for reproducing the information signals.

Master information magnetic recorder

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

A magnetic disk for a magnetic recording/reproduction device includes a magnetic head, wherein a magnetization bit-pattern corresponding to a preformat information signal is recorded beforehand on the magnetic disk, wherein the magnetization bit-pattern is recorded by contacting a surface of the magnetic disk with a surface of a master information carrier having a pattern corresponding to the preformat information signal, and a portion of the magnetization bit-pattern corresponding to at least one signal selected from a clock signal and a synchronous signal has a recording width that is larger than a recording track width of the magnetic head in a radial direction of the magnetic disk.

Magnetic recording/reproduction device using preformat information

A magnetic disk apparatus has: a head ( ) that performs data recording and playback while moving relative to a magnetic disk ( ) rotating at the prescribed speed; an actuator ( ) that positions said head relative to said magnetic disk ( ); and a controller ( ) that detects the position of said head by means of servo sector that have positioning information recorded magnetically on said magnetic disk ( ) and performs control to position said actuator ( ) by means of this detection signal, wherein said magnetic disk ( ) has at least a part in which the arrangement of tracks is spiral. The magnetic patterns on the disk include a servo sector and a data sector both formed on the same spiral track. The servo sector includes burst patterns for servo control.

Method and apparatus of forming a magnetic disk with a servo sector and a data sector on a spiral track

Master information carrier, process for producing the carrier, and method and apparatus for recording master information signal on magnetic recording medium by using the carrier

Growing community of inventors

Osaka, Japan

Kiyokazu Tohma