Abstract: The use of a Nd-YAG laser or excimer laser enables easy formation of protrusions on a protecting layer and a portion of an opposite surface near the trailing side end thereof and a thin film element. It is thus possible to avoid direct contact between the thin film element and the disk surface, and thus prevent damage to the thin film element and wearing thereof even if a slider and the disk surface repeatedly slide on each other.

Abstract: An optical waveguide element includes a substrate made of a lithium tantalate single crystal or a lithium niobate-lithium tantalate solid solution single crystal and a bulky optical waveguide made of a lithium niobate single crystal is directly joined to the substrate. The c-axis of the single crystal substrate is tilted at an angle with respect to the surface of the substrate to which the bulky optical waveguide is joined. The tilted angle is preferably within a range of 17-37 degrees.

Abstract: The use of a Nd-YAG laser or excimer laser enables easy formation of protrusions on a protecting layer and a portion of an opposite surface near the trailing side end thereof and a thin film element. It is thus possible to avoid direct contact between the thin film element and the disk surface, and thus prevent damage to the thin film element and wearing thereof even if a slider and the disk surface repeatedly slide on each other.

Abstract: An optical waveguide element has a substrate made of a lithium tantalate single crystal or a lithium niobate-lithium tantalate solid solution single crystal and a bulky optical waveguide made of a lithium niobate single crystal directly joined the substrate. The c-axis of the single crystal to constitute the substrate is tilted from the surface of the substrate to be joined preferably by 17-37 degrees.

Abstract: A composite metallic wire includes: an inner layer having a cross-sectional shape of a rough circle; and a metal outer layer having a cross-sectional shape of a rough ring; wherein the composite metallic wire has a diameter of 15 &mgr;m or less and an electric resistance of 300 &OHgr;/m or less. A composite type magnetic head using as a coil wire a composite wire comprising: (1) a composite metallic wire comprising: an inner layer having a cross-sectional shape of a rough circle; and a metal outer layer having a cross-sectional shape of a rough ring; wherein the composite metallic wire has a diameter of 15 &mgr;m or less and an electric resistance of 300 &OHgr;/m or less, and (2) an insulating coat provided in the outer periphery of the outer layer.

Abstract: A composite metallic wire includes: an inner layer having a cross-sectional shape of a rough circle; and a metal outer layer having a cross-sectional shape of a rough ring; wherein the composite metallic wire has a diameter of 15 .mu.m or less and an electric resistance of 300 .OMEGA./m or less. A composite type magnetic head using as a coil wire a composite wire comprising: (1) a composite metallic wire comprising: an inner layer having a cross-sectional shape of a rough circle; and a metal outer layer having a cross-sectional shape of a rough ring; wherein the composite metallic wire has a diameter of 15 .mu.m or less and an electric resistance of 300 .OMEGA./m or less, and (2) an insulating coat provided in the outer periphery of the outer layer.

Abstract: A magnetic head core slider including an air bearing and a core portion with a magnetic gap provided adjacent one of lengthwise opposite ends of the air bearing. A preliminary track is defined by preliminary width-defining grooves such that the preliminary track extends across the magnetic gap in the direction of extension of the air bearing, each groove having a depth larger than the depth of the magnetic gap. An effective track is defined by a pair of opposed final width-defining recesses formed adjacent to the magnetic gap such that the effective track extends across the magnetic gap in the direction of extension of the air bearing. The length and width of the effective track are smaller than those of the preliminary track, and the width of the effective track determines the nominal width of the magnetic gap. Each recess has a depth smaller than that of the preliminary width-defining grooves but larger than that of the magnetic gap. Also disclosed is a process of fabricating the head core slider.

Abstract: A composite type magnetic head core slider including a slider body and a core chip, wherein a slot is formed in the slider body such that the slot is open in an end face of the slider body and located within a width of a central recessed portion between two parallel air-bearing portions formed on a surface of the slider body which is to face a magnetic disk, or within a width of an outer recessed portion disposed on one side of one of the air-bearing portions, which one side is remote from the central recessed portion. The core chip is fixed in the slot such that an upper end portion of the core chip protrudes above a surface of the central or outer recessed portion, and the protruding upper end portion of the core chip is subjected to an operation to form a track portion having a magnetic gap.

Abstract: A ferrite plate and a ceramic plate are joined to each other by a glass layer interposed therebetween. The ferrite plate and the ceramic plate thus joined to each other by the glass layer serve as a trailing core in the form of a composite for use in a magnetic head. Only the ferrite plate is exposed on a slidable surface to prevent the trailing core from being deformed or cracked. The trailing core has low inductance for high-density recording to prevent the magnetic head from causing recording/reading errors.

Abstract: A thin-film magnetic circuit board is disclosed which includes: a substrate formed of a non-magnetic material; a connector formed from a magnetic film on one major surface of the substrate, the connector having opposite end portions which protrude from the substrate to form a pair of protrusions; at least one coil formed from an electrically conductive film to provide a circuit pattern on the one major surface of the substrate, each coil having a spiral shape and surrounding a corresponding one of at least one of the protrusions of the connector; and a pair of leads which are electrically connected to opposite ends of the circuit pattern formed by the coil(s). Also is disclosed a magnetic head including this thin-film magnetic circuit board and a core element having a magnetic gap.

Abstract: A core chip for a magnetic head core slider, including a first and a second core member which are bonded together so as to define a coil-winding aperture. The two core members cooperate to provide a gap-forming portion defining a magnetic gap on one side of the coil-winding aperture, and a cut-off portion provided adjacent to the gap-forming portion. The cut-off portion is removed by grinding at the top surface to establish the nominal depth of the magnetic gap. The cut-off portion has a distance marker which extends from the top surface down to the gap-forming portion and which has an end portion adjacent to the gap-forming portion. The end portion is shaped so as to indicate a distance between the top surface and the gap-forming portion, that is, the depth of the magnetic gap, when the cut-off portion is removed to provide a sliding surface of the core chip in which the magnetic gap is open. Also disclosed is a process of fabricating the magnetic head core slider using the core chip.

Abstract: A thin-film magnetic circuit board is disclosed which includes: a first and a second substrate formed of a magnetic material; a non-magnetic layer for bonding these substrates to each other; at least one coil formed from an electrically conductive film to provide a circuit pattern, each coil having a spiral shape and surrounding a predetermined blank portion of at least one of the first and second substrates; a pair of leads which are electrically connected to opposite ends of the circuit pattern formed by the coil(s); and a connector formed from a magnetic film, for magnetically connecting the first and second substrates. The connector is fixed to the predetermined blank portion of the first and/or second substrates. Also is disclosed a magnetic head including this thin-film magnetic circuit board.

Abstract: A method of producing a magnetic head core having a coil-winding groove around which an annular magnetic path is formed, and a magnetic gap intersecting the magnetic path, and a track having a predetermined track width and extending in a direction perpendicular to the magnetic gap, the magnetic gap and track being formed in a medium-sliding surface of the head core. The method includes the steps of: forming a track precursor in a surface of a core body which gives the medium-sliding surface of the head core, the track precursor having a larger width than a predetermined track width, and extending across the magnetic gap in a longitudinal direction of the core body; and pressing a shearing tool against the track precursor, and applying a force to the shearing tool to thereby remove by shearing at least one of widthwise opposite portions of the track precursor adjacent to the magnetic gap, so as to form the track having a predetermined track width in the vicinity of the magnetic gap.

Abstract: Method of producing a core slider for a rigid magnetic disk drive, including a slider body having air bearing portions, and a core chip which has a magnetic gap for writing and reading information and which is integrally secured to the slider body. The slider body consists of a ferrite section which includes at least the air bearing portions and which is formed of Mn--Zn ferrite, and a non-magnetic ceramic section formed of a non-magnetic ceramic material. The core chip is accommodated in a groove formed in the slider body and bonded to the slider body by a glass material.

Abstract: A thin-film magnetic head including: a slider body formed of a ferrite material and having air bearing portions on one major surface thereof on which a magnetic recording medium is slidable; a non-magnetic layer formed in the slider body such that the non-magnetic layer is located at least on a trailing end face of each of the air bearing portions, the non-magnetic layer having a thickness of at least 20 .mu.m; a head portion including an upper and a lower magnetic layer and a coil which are positioned within an area of the non-magnetic layer. The lower magnetic layer, the coil and the upper magnetic layer are laminated on the non-magnetic layer such that the upper and lower magnetic layers constitute a closed magnetic path, and such that a magnetic gap is formed between the upper and lower magnetic layers and is open in a top face of each air bearing portion.

Abstract: A core chip for a magnetic head core slider, including a first and a second core member which are bonded together so as to define a coil-winding aperture. The two core members cooperate to provide a gap-forming portion defining a magnetic gap on one side of the coil-winding aperture, and a cut-off portion provided adjacent to the gap-forming portion. The cut-off portion is removed by grinding at the top surface to establish the nominal depth of the magnetic gap. The cut-off portion has a distance marker which extends from the top surface down to the gap-forming portion and which has an end portion adjacent to the gap-forming portion. The end portion is shaped so as to indicate a distance between the top surface and the gap-forming portion, that is, the depth of the magnetic gap, when the cut-off portion is removed to provide a sliding surface of the core chip in which the magnetic gap is open. Also disclosed is a process of fabricating the magnetic head core slider using the core chip.

Abstract: A core slider for a rigid magnetic disk drive, including a slider body having air bearing portions, and a core chip which has a magnetic gap for writing and reading information and which is integrally secured to the slider body. The slider body consists of a ferrite section which includes at least the air bearing portions and which is formed of Mn-Zn ferrite, and a non-magnetic ceramic section formed of a non-magnetic ceramic material. The core chip is accommodated in a groove formed in the slider body and bonded to the slider body by a glass material.

Abstract: A composite magnetic head core with a writing/reading track and two erasing tracks, including a first ferrite block, and a second and a third ferrite block bonded to opposite surfaces of the first block interposed therebetween. The opposite abutting surfaces of the first block have respective first and second recessed portions, and a first rectangular protrusion and two second rectangular protrusions which protrude from the first and second recessed portions, respectively. The first protrusion is positioned between the two second protrusions in a direction of width of the writing/reading and erasing tracks. The first protrusion cooperates with the second block, to define a writing/reading magnetic gap of the writing/reading track, while the second protrusions cooperate with the third block, to define two erasing magnetic gaps of the erasing tracks. The first protrusion has a width defining the width of the writing/reading track, and a longitudinal end defining a depth of the writing/reading magnetic gap.

Abstract: A head core slider for a rigid magnetic disk drive, including a slider body, a track portion, a yoke portion and a narrow stepped portion. The slider body has two spaced-apart parallel air bearing portions, and the track portion is formed integrally with at least one of the bearing portions, so as to extend from one end of the bearing portion in the direction of length of the bearing portion. The track portion has the same height as the bearing portion, and a width smaller than that of the bearing portion. The yoke portion is formed integrally with the track portion, so as to extend from one end of the track portion remote from the bearing portion, and has a protrusion of the same height as the track portion. The width of the protrusion is smaller than that of the bearing portion and larger than that of the track portion.

Abstract: An optical unit having an electrooptical element whose optical properties are changed as a function of a voltage applied thereto to modulate an incident light in response to the applied voltage. The optical unit includes a shielding member for electrically shielding at least a portion thereof which includes the electrooptical element from an external electric field. The shielding member protects the electrooptical element from an influence of an external electric field on an electrooptical effect of the electrooptical element. The shielding member may be an electrically conductive member, such as a metallic casing accommodating the electrooptical element, or an electrically conductive layer covering a housing accommodating the element.