Hitachi, Ltd.

Hitachi Global Storage Technologies Japan, Ltd.

Hitachi Global Storage Technologies

Takayuki Munemoto

Hisashi Takano

Masaaki Futamoto

Yoshibumi Matsuda

Mikio Suzuki

Kyo Akagi

Takeshi Nakao

Yoshinori Miyamura

Fumio Kugiya

Hirotsugu Fukuoka

Tokuho Takagaki

Toshio Kobayashi

Hideo Tanabe

Naoki Koyama

Kazuo Shiiki

Masahiro Kitada

Isamu Yuito

Ryoichi Nakatani

Noboru Shimizu

Eijin Moriwaki

Shigemitsu Higuchi

Kenmei Masuda

Kazuo Sakai

Fumio Takeda

Fujio Tajima

Tomokazu Ishii

Shigeyuki Kobata

Nobuyuki Kaku

Hideki Sawaguchi

Takeshi Itoh

Nobuyuki Inaba

Kenji Ogiro

Kenji Mori

Taichiro Yamashita

Takao Terayama

Hajime Aoi

Yuzo Yamaguchi

Yosuke Seo

Fukuyasu Abe

Makoto Aihara

Kooetsu Okuyama

Kouetsu Okuyama

The magnetoresistance effect element is of a multilayered structure having at least magnetic layers and an intermediate layer of an insulating material, a semiconductor or an antiferromagnetic material against the magnetic layers, and the magnetoresistance effect element has terminals formed at least on the opposite magnetic layers, respectively, so that a current flows in the intermediate layer. The film surfaces of all the magnetic layers constituting the magnetoresistance effect element are opposed substantially at right angles to the recording surface of a magnetic recording medium. Therefore, the area of the magnetic layers facing the recording surface of the magnetic recording medium can be extremely reduced, and thus the magnetic field from a very narrow region of the high-density recorded magnetic recording medium can be detected by the current which has a tunneling characteristic and passes through the intermediate layer.

Method for manufacturing magnetic head device

Magnetic apparatus with perpendicular recording medium and head having multilayered reproducing element using tunneling effect

The magnetoresistance effect element is of a multilayered structure having at least magnetic layers and an intermediate layer of an insulating material, a semiconductor or an antiferromagnetic material against the magnetic layers, and the magnetoresistance effect element has terminals formed at least on the opposite magnetic layers, respectively, so that a all the magnetic layers constituting the magnetoresistance effect element are opposed substantially at right angles to the recording surface of a magnetic recording medium. Therefore, the area of the magnetic layers facing the recording surface of the magnetic recording medium can be extremely reduced, and thus the magnetic field from a very narrow region of the high-density recorded magnetic recording medium can be detected by the current which has a tunneling characteristic and passes through the intermediate layer.

Magnetic head with conductors formed on endlayers of a multilayer film having magnetic layer coercive force difference

Magnetic disk apparatus including magnetic head having multilayered reproducing element using tunneling effect

The magnetoresistance effect element is of a multilayered structure having at least magnetic layers and an intermediate layer of an insulating material, a semicondutor or an antiferromagnetic material against the magnetic layers, and the magneto-resistance effect element has terminals formed at least on the opposite magnetic layers, respectively, so that a current flows in the intermediate layer. The film surfaces of all the magnetic layers constituting the magnetoresistance effect element are opposed substantially at right angles to the recording surface of a magnetic recording medium. Therefore, the area of the magnetic layers facing the recording surface of the magnetic recording medium can be extremely reduced, and thus the magnetic field from a very narrow region of the high-density recorded magnetic recording medium can be detected by the current which has a tunneling characteristic and passes through the intermediate layer.

Magnetoresistance effect elements and magnetic heads using the tunneling magnetoresistive effect

The magnetoresistance effect element is of a multilayered structure having at least magnetic layers and an intermediate layer of an insulating material, a semiconductor or an antiferromagnetic material against the magnetic layers, and the magnetoresistance effect element has terminals formed at least on the opposite magnetic layers, respectively, so that a current flows in the intermediate layer. The film surfaces of all the magnetic layers constituting the magnetoresistance effect element are opposed substantially at right angles to the recording surface of a magnetic recording medium. Therefore, the area of the magnetic layers facing the recording surface of the magnetic recording medium can be extremely reduced, and thus the magnetic field from a very narrow region of the high-denisity recorded magnetic recording medium can be detected by the current which has a tunneling characteristic and passes through the intermediate layer.

Magnetoresistance effect multilayer film with ferromagnetic film

As a method of increasing the storage capacity of a magnetic recording and reproducing apparatus for recording and reproducing information to and from a magnetic tape in a cartridge, there is a helical scan recording method in which the magnetic tape is diagonally wound around a drum which rotates a magnetic head. With an apparatus adapted to this method, the disposition of the cartridge and the take-up reel for taking up the magnetic tape on the same plane arises a necessity of considerably bending the magnetic tape at the drum portion and, accordingly, the magnetic tape is damaged. In order to prevent the damage of the foregoing type, the tape passage surface from the cartridge to the drum and the tape passage from the drum to the take-up reel are formed by an angle at which the direction in which the magnetic tape is moved is changed due to winding of the magnetic tape around the drum so that the magnetic tape is not bent excessively. A threading device capable of three-dimensionally controlling the position of the magnetic tape in accordance with a predetermined tape passage is provided for the apparatus structured as described above. The threading device is formed by a link mechanism to be moved along the locus of a cam groove so that the three-dimensional position control can be performed.

Magnetic recording and reproducing apparatus

A magnetic recording medium, its fabrication method, and a magnetic recording apparatus in which both saturation induction and coercive force of a magnetic film is made high as they are near a surface of the recording medium. A high density information recording can be made higher than 50 kFCI in linear recording density even for spacing around 0.2 .mu.m.

Magnetic recording medium having at least two magnetic layers with easy

Multilayer magnetoresistance effect-type magnetic head

A method and device of head positioning in an information recording/reading device in which a magnetic recording medium with data tracks for recording information thereon is provided and a magnetic head is positioned on the data track to record/read out the information, wherein a data signal is recorded in the data recording layer of said recording medium, a servo signal is recorded in the servo signal recording layer located below said data signal recording layer, said data signal is read out using a data magnetic head whereas said servo signal is read out using a servo magnetic head, and the frequency of said servo signal is within the range of the gap-null frequency of said data magnetic head whereas the frequency of said data signal is within the range of the gap-null frequency of said servo magnetic head, and said magnetic head is positioned on the data track on the basis of said servo signal. A method and device of head positioning in an information recording/reading device in which a magnetic recording medium with data tracks for recording information thereon is provided and a magnetic head is positioned on the data track to record/read out the information, wherein the data tracks are discrete tracks in which adjacent data tracks are separated by a groove located therebetween, a data signal is recorded on the data track of said recording medium, a servo signal is recorded on the servo tracks of grooves between said adjacent data tracks, and said magnetic head is positioned on the data track on the basis of said servo signal.

Method of head positioning and magnetic recording disk drive using the

A magnetic recording and reproducing device and a magnetic tape library device are provided for properly recovering a function and issuing a warning when a failure of a magnetic head of the device takes place because of wear and dirt of the magnetic head. Further, a method for maintaining the magnetic head is provided. A wear sensor and a dirt sensor are prepared for sensing a wear amount of a state of dirt of the magnetic head. A head check controller operates to determine the wear amount of the magnetic head and the state of dirt based on the sensed result. In accordance with the determined result, the warning device is started for taking a precaution of preventing a head failure. As one aspect, the tape library device instructs to load the cleaning tape using a robot.

Magnetic tape library device and method for maintaining magnetic

The magnetoresistance effect element is of a multilayered structure having at least magnetic layers and an intermediate layer of an insulating material, a semiconductor or an antiferromagnetic material against the magnetic layers, and the magneto-resistance effect element has terminals formed at least on the opposite magnetic layers, respectively, so that a current flows in the intermediate layer. The film surfaces of all the magnetic layers constituting the magnetoresistance effect element are opposed substantially at right angles to the recording surface of a magnetic recording medium. Therefore, the area of the magnetic layers facing the recording surface of the magnetic recording medium can be extremely reduced, and thus the magnetic field from a very narrow region of the high-density recorded magnetic recording medium can be detected by the current which has a tunneling characteristic and passes through the intermediate layer.

A magnetic recording data storage system includes a magnetic recording medium having pits formed therein, the pits defining recording tracks on the magnetic recording medium and being arranged in a staggered manner relative to respective center lines of the recording tracks, a magnetic head including an inductive element for recording data on the recording tracks and a magnetoresistive element for reproducing data from the recording tracks, one of (1) a unit for magnetically producing a signal from the pits, and (2) an optical unit for optically producing a signal from the pits, the optical unit including a laser for illuminating the pits, servo means for positioning the head on the recording tracks based on the signal produced from the pits, the servo means including a dual-stage actuator including a rough movement portion and a fine movement portion.

Magnetic recording data storage system

In a rotary-disk transducer position control apparatus and method in which positional information concerning a transducer relative to a rotary disk based on a signal is obtained from the transducer which is disposed in opposition to the rotary disk, a seek instruction is inputted through an input device so that a first transducer access mechanism is caused to make the transducer perform a seeking operation at a low speed with a large stroke in accordance with both the positional information and the seek instruction, and in order to make the transducer perform both a seeking operation and a following operation, a second transducer access mechanism is caused to drive the transducer at a high speed with a small stroke in accordance with the positional information and the seek instruction.

Dual-actuator transducer position control apparatus for seeking and

Growing community of inventors

Ibaraki-ken, Japan

Takayuki Munemoto