Tdk Corporation

Nissan Motor Company Limited

Mitsubishi Chemical Corporation

Mitsubishi Heavy Industries Limited

Makoto Moriya

Akimasa Kaizu

Yoshikazu Soeno

Kazuya Shimakawa

Yoshikazu Saito

Kuniyasu Ito

Masaaki Kiura

Takahiro Mukuda

Masashi Serizawa

Hiroyuki Fukuoka

Kenichi Takano

Tomohito Mizuno

Haruo Mochida

Kazuhiro Hattori

Hiroshi Kiyono

Shuichi Okawa

Katsumichi Tagami

Takahiro Suwa

Tatsuhiro Kobayashi

Satoshi Tomikawa

Makoto Ishida

Akihiro Terasaka

Isao Hayashi

Joji Masuda

Hideo Aizawa

Shogo Otobe

Kenji Kubo

Provided is a composite material bonding apparatus that can reduce a cycle time when composite material members are bonded to each other. The composite material bonding apparatus includes a sheet-heater moving device that places a graphite heater at an insertion position between a first bonded surface of a first composite material member and a second bonded surface of a second composite material member such that the graphite heater is parallel to the first bonded surface and the second bonded surface facing the first bonded surface, and retracts the graphite heater to a retraction position from the insertion position. The first bonded surface and the second bonded surface are heated at the insertion position by the graphite heater, and then the graphite heater is moved to the retraction position by the sheet-heater moving device.

Composite material bonding apparatus and composite material bonding method

Particles of an acrylic polymer comprising a constituent unit (A) derived from methyl methacrylate and a constituent unit (B) derived from a (meth)acrylic acid alkyl ester in which the alkyl group has 2 to 8 carbon atoms, wherein the particles having electrostatic buildup inhibition rate of 90 to 99.9&#xb0; as obtained by a specific method.

Acrylic polymer particles, production process therefor, ink composition, and coating composition

Particles of an acrylic polymer comprising a constituent unit (A) derived from methyl methacrylic acid and a constituent unit (B) derived from a (meth)acrylic acid alkyl ester in which the alkyl group has 2 to 8 carbon atoms, wherein the particles having electrostatic buildup inhibition rate of 90 to 99.9%.

Using a thermally assisted magnetic recording head, reference signals are recorded into a magnetic recording medium; reproduction signal intensity of the reference signals is measured in a state where the thermally assisted magnetic head has been moved in the track width direction from the track width center of the track where the reference signals are recorded; a mean signal output of each sector in the track where the reference signals are recorded is calculated from the measurement results of the reproduction signal intensity of the reference signals; and the recording characteristics of a thermally assisted magnetic head are evaluated based upon the mean signal output of the sectors.

Method of assessing recording characteristics of thermally assisted magnetic head

Using a thermally-assisted magnetic recording device, a reference signal is recorded to a magnetic recording medium. After heating each of first and second heating points, where the first and second heating point being positioned respectively at inner and outer sides along a track width direction with respect to a track width center point of a recording bit where the reference signal is recorded, the reproducing signal intensity of the reference signal is measured. Then, obtaining a maximum distance between the first heating point and the second heating point when a reproducing signal intensity measurement value of the reference signal after the magnetic recording medium is heated is approximately zero. Based on the maximum distance, a characterization of the thermally-assisted magnetic recording device is evaluated.

Method for characterization evaluation of thermally-assisted magnetic recording device

A magnetic recording medium enhances the quality of a reproducing signal. The magnetic recording medium has a servo pattern formed in a servo pattern area on at least one surface of a disk-shaped substrate by a concave/convex pattern having convex portions (recording areas) and concave portions (non-recording areas), and a data track pattern formed by the concave/convex pattern in a data recording area on the at least one surface of the disk-shaped substrate. In a state where recording data is not recorded in the data recording area, the convex portions in the servo pattern area are DC-magnetized, and the convex portions in the data recording area are AC-magnetized.

Magnetic recording medium, recording and reproducing device, magnetic recording medium-magnetizing method, and magnetic recording medium-magnetizing device

On a magnetic recording medium, M sets of burst patterns are formed along a direction of rotation of a substrate in each burst pattern region. Each burst pattern is formed so as to include two types of burst signal units that have an equal length along a radial direction of the substrate. In a predetermined range (2&#xb7;M) centers in the radial direction of the burst patterns are present at intervals of (1/N) times the track pitch in the radial direction. The predetermined range has a length along the radial direction of (2M/N) times the track pitch. M or N is a natural number of two or higher. The two types of burst signal units are formed of non-recording regions and facing end parts in the radial direction of the first type of burst signal units and the second type of burst signal units are separated via recording regions.

Magnetic recording medium, recording/reproducing apparatus, and stamper

Data track pattern regions, in which data track patterns are formed by concave/convex patterns, and servo pattern regions, in which servo patterns are formed by concave/convex patterns, are provided on a magnetic recording medium so as to be alternately disposed in a circumferential direction. At least one predetermined region that differs to the data track pattern regions is provided between two servo pattern regions that are adjacent in a circumferential direction. A concave/convex pattern including a plurality of first convex parts formed continuously in a radial direction is formed in each predetermined region.

Magnetic recording medium, stamper recording/reproducing apparatus and method of measuring a parameter

A recording/reproducing apparatus includes: a rotary-type magnetic recording medium including a track pattern with concentric or spiral data recording tracks; a composite magnetic head including a reproducing element that reads magnetic signals from the medium and a recording element that writes magnetic signals on the medium; a control unit that moves the magnetic head over the medium to carry out tracking servo control on the reproducing element or the recording element to keep the element on a desired track; and a storage unit that stores offset information that specifies offsets for calculating an adjustment used to adjust a head position of the magnetic head during tracking servo control. The stored offset information specifies at least two different offsets per revolution of the medium. During tracking servo control, the control unit changes the adjustment at least once per revolution of the medium in accordance with offsets specified based on the offset information.

Recording/reproducing apparatus and tracking servo control method

On a magnetic recording medium, M sets of burst patterns are formed along a direction of rotation of a substrate in each burst pattern region. Each burst pattern is formed so as to include two types of burst signal units that have an equal length along a radial direction of the substrate. In a predetermined range, (2M) centers in the radial direction of the burst patterns are present at intervals of (1/N) times the track pitch in the radial direction. The predetermined range has a length along the radial direction of (2M/N) times the track pitch. M or N is a natural number of 2 or higher. The two types of burst signal units are formed of non-recording regions and end regions of the burst signal units overlap in the radial direction in at least one part region of the substrate.

Magnetic recording medium, recording reproducing apparatus, and stamper

An information recording medium excellent in surface smoothness. The information recording medium has a data track pattern and a servo pattern formed on at least one surface of a substrate by a concave/convex pattern including a plurality of convex portions. The concave/convex pattern has concave portions each having a non-magnetic material embedded therein. An A concave/convex pattern forming the servo pattern includes a plurality of servo convex portions formed in a manner associated with servo data. At least part of the plurality of servo convex portions are formed by a B concave/convex pattern including a plurality of non-servo convex portions. This arrangement makes it possible to maintain excellent surface smoothness within a servo pattern area, thereby enabling the recording/reproducing apparatus to execute stable recording and reproducing on and from the information recording medium.

Information recording medium and recording/reproducing apparatus

On a rotary-type magnetic recording medium, servo patterns are formed in servo pattern regions on one surface and the other surface of a disk-shaped substrate by patterns including recording regions and non-recording regions. In the servo pattern regions on both the one surface and the other surface, plural functional regions are defined in order in a direction of rotation of the magnetic recording medium. In the pattern formed in at least one region out of the plural functional regions on the one surface, the non-recording regions are formed at formation positions on the one surface corresponding to formation positions of the recording regions on the other surface and the recording regions are formed at formation positions on the one surface corresponding to formation positions of the non-recording regions on the other surface.

Magnetic recording medium, recording/reproducing apparatus, and stamper for manufacturing a magnetic recording medium

A recording/reproducing apparatus includes: a magnetic recording medium on which data track patterns are formed in data track pattern regions by a pattern with recording regions and non-recording regions and on which servo patterns are formed in servo pattern regions by the pattern; a recording head that writes signals on the medium; a reproducing head that reads signals written on the medium; and a control unit that controls the writing of signals by the recording head and the reading of signals by the reproducing head and measures a predetermined parameter for at least one of the recording head and the reproducing head by writing and reading measurement signals on the medium. The control unit writes the measurement signals using the recording head on first recording regions formed continuously in a radial direction of the medium out of the recording regions formed in the servo pattern regions, reads the measurement signals using the reproducing head, and measures the parameter based on the read measurement signals.

Recording/reproducing apparatus and method of measuring a parameter

On a magnetic recording medium, M sets of burst patterns are formed along a direction of rotation of a substrate in each burst pattern region, where M is a natural number of two or higher. Each burst pattern is formed so as to include two types of burst signal units that are positioned at different distances from a center of data track patterns and have an equal length along a radial direction of the substrate. The length along the radial direction is (2&#xb7;M/N) times the track pitch, where N is a natural number of two or higher. In a predetermined range where both ends in the radial direction do not match a center in the radial direction of a burst pattern, (2&#xb7;M) centers in the radial direction of the burst patterns are present at intervals of (1/N) times the track pitch in the radial direction, the two types of burst signal units are formed of non-recording regions and do not overlap each other in the direction of rotation, centers of the burst signal units in the radial direction are separated by (M/N) times the track pitch, and facing end parts in the radial direction of the burst signal units are separated via recording regions.

On a magnetic recording medium, M sets of burst patterns are formed along a direction of rotation of a substrate in each burst pattern region, where M is a natural number of two or higher. Each burst pattern is formed so as to include two types of burst signal units that are positioned at different distances from a center of data track patterns and have an equal length along a radial direction of the substrate. The length along the radial direction is (2&#xb7;M/N) times the track pitch, where N is a natural number of two or higher. In a predetermined range where both ends in the radial direction do not match a center in the radial direction of a burst pattern, (2&#xb7;M) centers in the radial direction of the burst patterns are present at intervals of (1/N) times the track pitch in the radial direction, the two types of burst signal units are formed of recording regions and do not overlap each other in the direction of rotation, centers of the burst signal units in the radial direction are separated by (M/N) times the track pitch, and facing end parts in the radial direction of the burst signal units are separated via non-recording regions.

Growing community of inventors

Tokyo, Japan

Makoto Moriya