Matsushita Electric Industrial Co., Ltd.

Keizou Miyata

Tatsuaki Ishida

Kiyokazu Tohma

Ryuji Sugita

Hiroshi Ryonai

Kazunari Yoshimoto

Kenji Hasegawa

Norimoto Nouchi

Taizou Hamada

Masaya Sakaguchi

Yoshiaki Mizoh

Tetsuo Fuchi

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

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

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

An underlying layer is formed of Cr or the like on a glass substrate, and a magnetic layer is formed on the underlying layer by simultaneously sputtering a magnetic substance and a non-magnetic substance that does not form a solid solution with the magnetic substance in an atmosphere having a pressure of 30 mTorr to 75 mTorr. The magnetic recording medium comprises clusters, each of which is formed of aggregated magnetic grains, and a non-magnetic substance between the clusters. Each magnetic grain has a grain diameter of 5 nm to 20 nm. An average gap between the clusters is 1.5 nm to 5 nm. Thus, the present invention can provide a magnetic recording medium having a high S/N ratio that is suitable for high density recording.

Magnetic recording medium and method for producing the same

A head cleaner for a magnetic recording and/or reproducing apparatus for cleaning rotary magnetic heads. The head cleaner includes a rotary spindle rotatably mounted on a support arm movable between an operative position, in which the head cleaner is in position to clean the magnetic heads, and an inoperative position separated from the magnetic heads. The head cleaner also includes a plurality of oblong webs of non-woven fabric with or without an abrasive material coated on one surface thereof. The oblong webs of non-woven fabric are fixedly secured to the rotary spindle so as to extend radially outwardly therefrom while being spaced an equal distance from each other in a direction circumferentially thereof.

Tubular rotary head cleaner having a non-woven fabric for a magnetic

Head cleaner for magnetic recording/reproducing apparatus having a

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Moriguchi, Japan

Keizou Miyata