Matsushita Electric Industrial Co., Ltd.

Fujifilm Corporation

Fuji Photo Film Company, Limited

Ryuji Sugita

Tatsuaki Ishida

Kiyokazu Tohma

Kazunari Yoshimoto

Keizou Miyata

Kazuyoshi Honda

Yasuaki Ban

Makoto Nagao

Toshiaki Kunieda

Hiroshi Ryonai

Yasuhiro Kawawake

Takashi Komine

Kiyokazu Thoma

Ken Takahashi

Masakazu Nishikawa

Tadashi Yasunaga

Kenji Kanai

Noriyasu Echigo

Seishi Sasaki

Hiroyuki Hasegawa

Yoshiki Goto

Yoichi Nishida

Hideyuki Kubota

Yukihiro Shimasaki

Kazutoshi Katayama

Hiroshi Nishida

Kyoji Noda

Hideki Yoshida

Yoshiki Murakami

Yasuihiro Kawawake

Taro Nanbu

The present invention provides a magnetic transfer master carrier which forms a magnetic pattern corresponding to a pattern of information to be recorded on a perpendicular magnetic recording medium when a magnetic field is applied to the perpendicular magnetic recording medium, with the magnetic master carrier and the perpendicular magnetic recording medium closely attached to each other, the carrier including: a base material having convex portions on its surface, the convex portions being provided corresponding to the pattern of information; a magnetic layer deposited on at least top surfaces of the convex portions, and having perpendicular magnetic anisotropy; and a soft magnetic layer deposited on the surface of the magnetic layer.

Magnetic transfer master carrier, magnetic transfer method, and magnetic recording medium

A magnetic transfer master carrier of the present invention includes a base material having convex portions on its surface, the convex portions being provided corresponding to a pattern of information to be recorded on a perpendicular magnetic recording medium, and a magnetic layer deposited at least on top surfaces of the convex portions, wherein when a magnetic field is applied to the magnetic transfer master carrier, the magnetic layer absorbs a magnetic flux so as to form a pattern of the magnetic field, wherein the magnetic layer includes at least two perpendicular magnetic anisotropic layers, and an antiferromagnetic coupling induction layer which is provided so as to be sandwiched in between two neighboring layers of all the perpendicular magnetic anisotropic layers, and to induce antiferromagnetic coupling therebetween.

Magnetic transfer master carrier and magnetic transfer method

An amplitude servo pattern capable of providing accurate servo control through reproduced amplitude with reduced noise is provided. The amplitude servo pattern has servo burst signals composed of burst bit strings adjacently disposed in a track width direction. The burst bit strings are disposed such that the servo burst signals adjacently disposed in the track width direction have a phase difference with each other in a track direction.

Amplitude servo pattern, magnetic recording medium and the manufacturing method, patterned magnetic transfer master substrate used in the manufacturing method, and magnetic recording/reproducing apparatus

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 master information carrier for magnetic transfer includes a substrate having an irregularity pattern representing information to be transferred to a slave medium and a magnetic layer formed on the irregularity pattern on the substrate. The depth d of the recessed portions of the irregularity pattern and the thickness t of the magnetic layer formed on the recessed portions satisfy formula &#x2212;0.004&#x2266;(t&#x2212;d)/d&#x2266;0.1. At the same time, the magnetic layer formed on the protruding portion of the irregularity pattern and the magnetic layer formed on the recessed portions of the irregularity pattern are connected with each other.

Master information carrier for magnetic transfer

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

The present invention provides a master carrier for magnetic transfer, comprising a plurality of transfer information recording sectors having recording information magnetized thereon, a non-magnetic-material sector defining each of the transfer information recording sectors is present between each of adjacent transfer information recording sectors, and surfaces of the transfer information recording sectors and surfaces of the non-magnetic material sectors are positioned on and form the same plane.

Master carrier for magnetic transfer and method for transfer

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 apparatus for recording and reproducing a signal using a thin film magnetic tape as a medium and using ring type magnetic heads for recording and reproducing the signal, wherein the gap length of the magnetic head for reproducing is larger than the gap length of the magnetic head for recording. Maximum recording and reproducing performance is achieved by implementing separate recording and reproducing heads.

Magnetic recording and reproducing apparatus

In a magnetic recording and reproduction apparatus wherein signals are recorded with a ring-type magnetic head to a magnetic recording medium having axis of easy magnetization oblique with respect to a film normal of a magnetic layer of the medium A recording magnetic field generated by the magnetic head is asymmetric with respect to a center line of a gap of the magnetic circuit, and the recording magnetic field in the magnetic layer around a leading edge of the magnetic head is inclined at the same side as the axis of easy magnetization in the magnetic field in a normal plane of the magnetic layer including a direction of relative movement of the magnetic head to the magnetic recording medium when signals are recorded to the medium. Thus, signals can be recorded at a high density. Various types of magnetic head for generating asymmetric magnetic field are provided.

Magnetic recording and reproducing apparatus having ring-type magnetic

In a magnetic recording and reproduction apparatus wherein signals are recorded with a ring-type magnetic head to a magnetic recording medium having axis of easy magnetization oblique with respect to a film normal of a magnetic layer of the medium. A recording magnetic field generated by the magnetic head is asymmetric with respect to a center line of a gap of the magnetic circuit, and the recording magnetic field in the magnetic layer around a leading edge of the magnetic head is inclined at the same side as the axis of easy magnetization in the magnetic field in a normal plane of the magnetic layer including a direction of relative movement of the magnetic head to the magnetic recording medium when signals are recorded to the medium. Thus, signals can be recorded at a high density. Various types of magnetic head for generating asymmetric magnetic field are provided.

Magnetic recording and reproduction apparatus ring-type magnetic head

Growing community of inventors

Hirakata, Japan

Ryuji Sugita