Sony Corporation

Yutaka Soda

Tetsuo Sekiya

Munekatsu Fukuyama

Shigeyoshi Imakoshi

Norio Saito

Hideo Suyama

Hiroyuki Uchida

Tadashi Ozue

Satoru Seko

Koji Fukumoto

Susumu Sato

Yasuhiro Iida

Hiroki Tetsukawa

Takuji Shibata

Seiji Onoe

Junkichi Sugita

Yasuo Sasaki

Kenichi Baba

Yoshimi Takahashi

Keisuke Fujiwara

Noboru Wakabayashi

Koji Takahashi

Hitoshi Saito

Hiroaki Ono

Jin Sato

Kiyoshi Ota

Nobuyuki Nagai

Hiroshi Meguro

Hiroaki Yada

Teiichi Miyauchi

Hiroshi Takino

Fujio Kanai

Masaaki Sekine

Akihiko Okabe

Takehiro Nagaki

Iwao Abe

Katsuhiko Akiyama

Horoaki Yada

Hideko Imamura

Takeyuki Fuse

Katsuhiro Kasuga

A laser diode capable of being easily mounted and a laser diode device in which the laser diode is mounted are provided. A hole is disposed in a semiconductor layer, and a p-type electrode and an n-type semiconductor layer are electrically connected to each other by a bottom portion (a connecting portion) of the hole. Thereby, the p-type electrode has the same potential as the n-type semiconductor layer, and a saturable absorption region is formed in a region corresponding to a current path. Light generated in a gain region (not shown) is absorbed in the saturable absorption region so as to be converted into a current. The current is discharged to a ground via the p-side electrode and the bottom portion, an interaction between the saturable absorption region and the gain region is initiated, and thereby self-oscillation can be produced.

Magneto-resistance effect type magnetic head and magnetic tape apparatus

A magnetic recording/reproducing head having a plurality of magnetic head elements for multi-channeling capable of achieving high density recording/reproducing capability, including: a plurality of magnetic recording/reproducing head layers each including magnetic recording/reproducing head elements fabricated by a thin film process and interposed between two insulating/magnetic shielding layers laminated on a non-magnetic substrate; the total of magnetic recording/reproducing head elements formed therein are displaced from each other in a head width direction, and each magnetic recording/reproducing head layer has a plurality of magnetic recording/reproducing head elements formed at a predetermined pitch.

Magnetic recording/reproducing head with head elements displaced in both head width and lamination directions

A head substrate and a protective substrate are formed of an electrostatic-discharge resistant conductive material having an electrical resistivity of 10to 10&#x3a9;cm. These substrates are electrically connected to a base metal through the use of conductive paste and are set to a ground potential via the base metal and a rotating drum. This suppresses a discharge current flowing through an MR element when an electrostatically charged substance touches or approaches a magnetic reproducing head, a terminal, a conducting wire, etc. to generate an electrostatic discharge. The magnetic reproducing head including an MR element and the like is prevented against an electrostatic discharge damage. It is possible to provide the magnetic reproducing head, a head drum apparatus, and a magnetic recording-reproducing apparatus which can highly effectively prevent an electrostatic discharge damage.

Magnetic reproducing head having a structure to inhibit electrostatic discharge damage to a recording tape

A highly reliable magnetic recording/reproducing apparatus is provided. In the magnetic recording/reproducing apparatus, a spin-valve film is used as a magnetic sensor element for detecting magnetic signals. By defining the corrosion potential of this spin-valve film, and further by specifying the residual magnetization of a magnetic recording medium used as well as the product of the residual magnetization and the thickness of the magnetic layer to a range that is numerically optimal, the occurrence of corrosion on the surface of a magnetoresistive head that contacts the medium is prevented, and the occurrence of electromagnetic discharge is avoided. Further, by numerically specifying the surface resistivity of the metal magnetic thin film of the magnetic recording medium, as well as the roughness of the surface on which the metal magnetic thin film is formed, electrostatic discharge preventing effects and wear resistance are improved.

Magnetic recording/reproducing apparatus using a GMR head

Magnetic reproducing head having a structure to inhibit electrostatic discharge to a recording tape

An improvement in the corrosion resistance of a magnetoresistive head is aimed for, and a high magnetoresistivity ratio is maintained. In a magnetoresistive head equipped with, as a magnetic sensor element for detecting magnetic signals while in contact with a magnetic recording medium, a spin-valve film, which has a structure where an anti-ferromagnetic layer, a pinned layer in which the direction of magnetization is pinned in a predetermined direction by an exchange-coupling magnetic field at work between itself and the anti-ferromagnetic layer, a free layer in which the direction of magnetization changes in accordance with an external magnetic field, and a non-magnetic layer for magnetically isolating the pinned layer and the free layer are layered, the corrosion potential of the spin-valve film relative to a standard hydrogen electrode measured while immersed in a NaCl solution of a concentration of 0.1 mol/L is specified at +0.4 [V vs. SHE] or above.

Magnetoresistive head with spin valve film magnetic sensor element

The present invention provides a multi-magnetic recording head capable of increasing a magnetic recording density of information recorded on a magnetic recording medium. The multi-magnetic recording head includes a substrate, a pair of first thin film magnetic poles with a specific gap put therebetween, which are stacked over the substrate, and a pair of second thin film magnetic poles with a specific gap put therebetween, which are stacked over the pair of first thin film magnetic poles, wherein the pair of first thin film magnetic poles and the pair of second thin film magnetic poles are offset from each other in the direction nearly perpendicular to the stacking direction.

Multi-magnetic recording head, and magnetic recording method and magnetic recording apparatus using the same

A head substrate and a projection substrate of a head drum comprise a conductive material having a resistance of 1&times;10 &OHgr; or less and are connected to a metal base so as to be at the ground potential via the metal base and a rotating drum. These antistatic treatments allow static electricity charged on a magnetic tape to be discharged to the head substrate and the protection substrate without flowing to a magneto-resistive (MR) element, thereby preventing the electrostatic discharge breakdown of the MR element.

Magnetic recording and playback device with ESD protection

A magnetic head device in which magnetic head elements can follow the signal recording surface of the first or second magnetic disc . To this end, the magnetic head device includes a head unit for recording/reproducing information signals for the first or second magnetic disc , and a supporting arm having a first portion for supporting said head portion, a second portion mounted on a supporting arm holding portion and a third portion interconnecting said first and second portions and . The first to third portions to of the supporting arm are of different shapes so as to have different physical properties to follow the first or second magnetic disc under a desired condition.

Head assembly capable of reading floppy discs of varying densities and floppy-disc drive incorporating the same

To provide a head slider capable of enhancing the electromagnetic transductional characteristic of a magnetic head and a magnetic disk unit provided with the head slider, the head slider provided with a rail on each side and floated over a magnetic disk by air flow, the head slider for reading or recording information from/in the magnetic disk mounted on the rail on one side of the head slider, and the rails formed asymmetrically so that the floated quantity of the rail on the side on which the head slider is mounted is lower than the floated quantity of the rail on the side on which the head slider is not mounted.

Head slider with asymmetric air rails

A magnetic reluctance effect magnetic head in which a forward side electrode is stacked on at least the surface of a magnetic reluctance effect element facing a magnetic recording medium, and in which an upper magnetic pole is stacked on the forward side electrode for facing the magnetic reluctance effect element. A connecting length L1 between the magnetic reluctance effect element and the forward side electrode is shorter than a facing length L2 over which the upper magnetic pole and the magnetic reluctance effect element face each other via a magnetic gap G. The upper magnetic pole and the magnetic reluctance effect element have an area in which the upper magnetic pole and the magnetic reluctance effect element face each other over a distance g2 larger than a magnetic gap length g1 of the magnetic gap G. The upper magnetic pole may be formed to be progressively spaced apart from the magnetic reluctance effect element by being angled 30.degree. relative to the magnetic reluctance effect element, and the distance g2 may be progressively increased. With the magnetic reluctance effect magnetic head, the playback output may be improved and the magnetic head may be reduced in size and in the power consumption.

Magnetic reluctance effect magnetic head with the connection length of

A thin-film magnetic head, a magnetoresistance effect magnetic head and an MR inductive head are disclosed. The thin-film magnetic head has one of thin-film magnetic cores stacked on a substrate and formed of two magnetic films and a non-magnetic film held between them, with a current flowing through the thin-film magnetic core in the direction of hard axis thereof. The magnetoresistance effect magnetic head has one of a pair of shield cores having a magnetoresistive element between them formed of two magnetic films and a non-magnetic film held between them, the magnetoresistive element being electrically connected to the shield core, with a sense current flowing through the shield core. The current flowing through the one shield core via the magnetoresistive element is preferably an AC of decrement amplitude for demagnetizing the shield core along with a DC sense current. Also, this current preferably flows in the direction of hard axis of the shield core so that magnetic properties of the shield core are stabilized or demagnetized by the magnetic field generated in the direction of easy axis. The MR inductive head has a second thin-film magnetic core as a common magnetic body of an MR head and an inductive head on one substrate, formed of two magnetic films and a non-magnetic film held between them, with a current flowing through the second thin-film magnetic core in the direction of hard axis thereof.

Thin film magnetic head, magnetoresistance effect magnetic head and

A magneto-resistance effect-type magnetic head according to the present invention can generate a high reproduction output by increasing a quantity of magnetic flux passing across an effective magneto-sensitive zone of a magneto-resistance effect element, while maintaining its inherent functions as a means for preventing unnecessary magnetic flux from entering the MR element or as a recording pole. The magneto-resistance effect-type magnetic head for reproducing signals from a magnetic recording medium, includes a magneto-resistance effect element, upper and lower magnetic layers between which the magneto-resistance effect element is interposed, and a low-permeability magnetic layer provided on at least one of surfaces of the upper and lower magnetic layers which surfaces are opposed to the magneto-resistance effect element, the low-permeability magnetic layer having a magnetic permeability not more than half of a magnetic permeability of the upper or lower magnetic layer.

Magneto-resistance effect-type magnetic head

Thin-film magnetic head, magnetoresistance effect magnetic head and

A magneto-resistance effect magnetic head in which the MR effects of the two MR thin films of a MR device are balanced for suppressing Barkhausen noise and assuring a stabilized output. Between a lower-layer magnetic shield core and an upper layer magnetic shield core is arranged an MR device, made up of two MR thin films such that a distance d.sub.1 between the lower-layer magnetic shield core and the MR thin film is smaller than a distance d.sub.2 between the upper-layer magnetic shield core and the MR thin film. A film thickness t.sub.1 of the MR thin film towards the lower-layer magnetic shield core is set so as to be thinner than a film thickness t.sub.2 of the MR thin film towards the upper-layer magnetic shield core. Preferably, the relation 0.5&lt;t.sub.1 /t.sub.2 holds. Also, a resistivity .rho..sub.1 of the MR thin film closer to the lower layer magnetic shield core may be larger than a resistivity .rho..sub.2 of the MR thin film. Preferably, the relation .rho..sub.1 /.rho..sub.2 &gt;3 holds.

Magneto-resistance effect magnetic head

Growing community of inventors

Kanagawa, Japan

Yutaka Soda