Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A magneto-resistance effect type magnetic head is disclosed which is high in sensitivity and corrosion resistance. In the head, a spin valve film acting as an magnetic sensing device for detecting a magnetic signal on a magnetic recording medium. The spin valve film is structured such that an antiferromagnetic layer, a fixed magnetization layer whose magnetization direction is fixed by an exchange coupling magnetic field acting between the layers, a free magnetization layer whose magnetization direction varies in response to an external magnetic field, and a nonmagnetic layer for magnetically isolating the fixed magnetization layer and the free magnetization layer are laminated. The nonmagnetic layer is formed from a conductive layer, an interface layer formed on an interface between the fixed magnetization layer and conductive layer, and a second interface layer formed on an interface between the conductive layer and free magnetization layer.

Abstract: A head substrate and a protective substrate are formed of an electrostatic-discharge resistant conductive material having an electrical resistivity of 102 to 1010 ?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.

Abstract: 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.

Abstract: A head substrate and a protective substrate are formed of an electrostatic-discharge resistant conductive material having an electrical resistivity of 102 to 1010 ?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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A pair of reels of a magnetic cassette tape and a pair of reel supports of a magnetic tape drive comprise a conductive material as an antistatic treatment. Further, a head substrate and a projection substrate of a head drum comprise a conductive material having a resistance of 1×1010 &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.

Abstract: 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.

Abstract: A head substrate and a projection substrate of a head drum comprise a conductive material having a resistance of 1×1010&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.

Abstract: 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.

Abstract: A magnetic head device in which magnetic head elements can follow the signal recording surface of the first or second magnetic disc 6, 23. To this end, the magnetic head device includes a head unit 121 for recording/reproducing information signals for the first or second magnetic disc 6, 23, and a supporting arm 122 having a first portion 131 for supporting said head portion, a second portion 132 mounted on a supporting arm holding portion and a third portion 133 interconnecting said first and second portions 131 and 132. The first to third portions 131 to 133 of the supporting arm 122 are of different shapes so as to have different physical properties to follow the first or second magnetic disc 6, 23 under a desired condition.

Abstract: 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.

Abstract: An anti-static measure is taken against tape guide parts of a magnetic tape cassette by forming the tape guide parts of a conductive material and so on. An antistatic measure against a lid, an upper shell, a transparent window and a lower shell is taken by coating at least either of inside and outside of each of the lid, the upper shell, the transparent window and the lower shell with an anti-static film. A magnetic layer of a magnetic tape has a thickness of from 10 nm or more to 100 nm or less, and also contains oxygen in an amount of from 20 atm % or more to 30 atm % or less in a whole magnetic layer. An information recording surface of the magnetic tape has also a surface resistance of from 103&OHgr;/inch2 or more to 1012&OHgr;/inch2 or less.

Abstract: A pair of reels of a magnetic cassette tape and a pair of reel supports of a magnetic tape drive comprise a conductive material as an antistatic treatment. Further, a head substrate and a projection substrate of a head drum comprise a conductive material having a resistance of 1×1010 &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.