Abstract: A magnetic disc apparatus has a large recording density of 120 megabits per square inch or more, and defines a relationship among a pole thickness (Pt) of thin-film magnetic heads disposed in the magnetic disc apparatus, and a saturation flux density (Bs) of cores of the heads and a recording wavelength (.lambda.) for the thin film magnetic discs have a coercivity of 1800 Oe or more, wherein a levitation space between the head and the disc is 0.15 .mu.m or less.

Abstract: A flying head slider utilizing a negative pressure according to the invention has a front end, a rear end, and an air bearing surface directed to face a rotating recording medium. The air bearing surface includes a pair of side rails extending on both sides of the air bearing surface from the front end in the longitudinal direction of the slider, a center rail provided at the center of the air bearing surface in the transverse direction and extending from the front end to the rear end in the longitudinal direction of the slider, a cross rail extending in the transverse direction of the slider to connect the pair of side rails and the center rail to each other near the front end, a pair of recesses defined by the pair of side rails, the center rail and the cross rail, communicating grooves for communicating the pair of recesses with the front end, and a head mounted on a rear end surface of the center rail. The pair of side rails, the center rail and the cross rail lie substantially in the same plane.

Abstract: A magnetic head includes a gimbal with a head slider attached thereon, a load beam retained on the gimbal, and a mount attached on an end portion of the load beam on a side opposite to a side where the head slider is attached. A fulcrum portion as a center of load of the head slider is set on the gimbal to be shifted from a center of the head slider along its longitudinal direction to a proximal end side of the load beam, namely, toward an air upstream side. To compensate for the imbalance of the floating force due to the shift of the fulcrum portion, there is generated a moment about the fulcrum portion. The moment is provided by assigning an inclination angle to a slider attaching surface of the gimbal. The inclination angle can be adjusted by the height of the projection formed as the fulcrum portion. Moreover, the moment is generated by disposing rails on the head slider such that the width on the air upstream side of each rail is wider than the width on the air downstream side of the rail.

Abstract: A magnetic disc apparatus includes a magnetic disc for recording information; a thin film magnetic head including a magnetic pole structure having an upper magnetic pole tip and a lower magnetic pole tip arranged to provide a magnetic gap at respective end portions thereof for writing and reading information in and from the magnetic disc; a device for rotating the magnetic disc; and a device for positioning the thin film magnetic head; the upper and lower magnetic pole tips having different contours at the respective end portions as viewed from a side confronting the magnetic disc wherein the difference (.DELTA.CW in .mu.m) in the width, along the magnetic gap, of the upper magnetic pole tip and the width, along the magnetic gap, of the lower magnetic pole tip satisfies the relation0<.DELTA.CW.ltoreq.5000/Trfor the magnetic disc having a track density Tr of 1800 or more tracks per inch.

Abstract: A magnetic head for reading from and/or writing to a magnetic information storage medium has a substrate on which a plurality of thin films are formed in sequence. The films provide a magnetic circuit having a magnetic gap, a bottom pole piece and a top pole piece overlying said bottom pole piece. The top pole piece is formed as a tip portion adjoining the magnetic gap and a rear portion which makes magnetic contact with the tip portion. The rear portion is formed in the sequence after the tip portion. To ensure accurate thickness and width of the tip portion, a non-magnetic protective film is formed on the tip portion after the tip portion is formed and before the rear portion is formed.

Abstract: A head arm for use in a magnetic disk drive, comprising a guide arm disposed between a magnetic head and an actuator so as to transmit actuating force of the actuator to the magnetic head thereby guiding the magnetic head along a plane of a magnetic disk, a printed circuit fixed to the guide arm, and deflection compensating member for making the coefficients of thermal expansion of said guide arm and said printed circuit substantially equal to each other in at least the direction of seek of the head arm. No thermal deformation in an out-of-plane direction occurs on such a head arm regardless of any variation in the temperature of the environment in which the magnetic disk drive is installed. A head arm may also comprise a guide arm and a printed circuit formed of a moisture absorptive material and covered at all or part of its surfaces with a covering layer formed of a moisture resistive material not permeable to moisture.

Abstract: A head arm for use in a magnetic disk drive, comprising a guide arm disposed between a magnetic head and an actuator so as to transmit actuating force of the actuator to the magnetic head thereby guiding the magnetic head along a plane of a magnetic disk, a printed circuit fixed to the guide arm, and deflection compensating member for making the coefficients of thermal expansion of said guide arm and said printed circuit substantially equal to each other in at least the direction of seek of the head arm. No thermal deformation in an out-of-plane direction occurs on such a head arm regardless of any variation in the temperature of the environment in which the magnetic disk drive is installed. The head arm may also comprise a guide arm and a printed circuit formed of a moisture absorptive material and covered at all or part of its surfaces with a covering layer formed of a moisture resistive material not permeable to moisture.

Abstract: This invention provides a magnetic disk device having a total memory capacity of 30 giga bytes or more, or more desirably 30.about.40 giga bytes. The magnetic disk used in this magnetic disk device has a plane record density of 45.about.80 mega bits per square inch. The thin film magnetic head has a pole thickness (P.sub.T), a magnetic flux density (B.sub.s), a magnetic gap depth (G.sub.d) and a record wavelenth (.lambda.) which satisfy the formulaG.sub.d .ltoreq.0.13 P.sub.T B.sub.s (.lambda.+4.3)-2.1.The magnetic disk rotation means rotate the magnetic disk at a speed of 24 m per second or more.

Abstract: A compound magnetic head includes first and second magnetic poles arranged to face each other to define a recording gap therebetween, a magnetic film arranged between the first and second magnetic poles, a first non-magnetic film arranged between the first magnetic pole and the magnetic film to define a first reproducing gap therebetween, and a second non-magnetic film arranged between the second magnetic pole and the magnetic pole to define a second reproducing gap therebetween. The recording gap and the first and second reproducing gaps have the same width and a common center line of the gap widths parallel to the direction of movement of a magnetic recording medium.

Abstract: The present invention provides a magnetic disc file which comprises a thin film magnetic disc for recording information, a motor for rotating the thin film magnetic disc, a magnetic head for writing and reading information, the head being provided with a flying slider, and a carriage for supporting the magnetic head and changing the position of the head in respect of the thin film magnetic disc, the flying height of the flying slider from the thin film magnetic disc being set in the range of 0.05 to 0.15 .mu.m, and the slider being not in contact with the thin film magnetic disc during the seeking operation on the thin film magnetic disc, the slider being a sintered body containing a metal oxide or oxides in an amount of 50 vol % or more based on the total of said body and containing 0.

Abstract: The present invention provides; a magnetic disk recorder comprising (i) magnetic disks having magnetic recording media, (ii) thin-film magnetic heads for recording information in the recording media and reproducing information therefrom, and (iii) a carriage for moving the magnetic heads to intended positions, the recorder being wherein the thin-film magnetic heads are formed on sliders and these sliders comprise sintered bodies containing a non-magnetic metal oxide of spinel structure and harder ceramic particles than the metal oxide which are dispersed in the metal oxide; a sintered body useful particularly as a material for the magnetic head slider, a method for making the sintered body, and a magnetic head and a magnetic head slider, for recording and reproducing information, which are made by using the sintered body.

Abstract: A thin film magnetic head has magnetic films, at least one of which is composed of a material containing major components of nickel and iron and one or more element from nitrogen, oxygen and carbon and has two of face-centered cubic system and body-centered tetragonal system, whereby thin film magnetic heads having a high permeability and low coercive force can be provided.

Abstract: An apparatus for supporting and reciprocating a magnetic head slider above a rotating magnetic disk comprises a carrying arm having a free end, a flexible base connected at one end thereof to the free end of the supporting arm, a pair of flexible fingers extending from the other end of the flexible base parallel to an axis of the carrying arm and defining therebetween a space, a traverse bar connecting two free ends of the fingers, and a flexible tongued member on which the magnetic head slider to be mounted, one end of the tongued member being connected to the traverse bar and the other end thereof extending into the space with gaps between the tongued member and the fingers and the base. A reduced part of a minimum cross-section is provided in each of the fingers. The reduced part is located between the one end of the tongued member and a center between the one end of the tongued member and the other end of the base.

Abstract: A transducer supporting apparatus is provided with a rigid structural support connected to a rigid arm portion and a flexible strucural support provided on the free end of the rigid structural support, the flexible structural support comprising two flexible fingers, a transverse frame connecting the two flexible fingers on the extending side thereof through steps, and a slider mounting portion having a tongue form which extends from this frame and is provided adjacent to the two flexible fingers and a slider loaded with a transducer being junctioned with the slider mounting portion. The flexible fingers are so configurated that the end thereof on the side of the rigid arm portion is brought nearer to the plane formed by the floating surface of the slider than the end thereof on the side of the slider mounting portion.

Abstract: The invention designed to improve the precision in determining the position of the magnetic head and to enable more stable maintenance of the gap between the transducer and the recording disk is characterized in that the flange provided to the transducer supporting arm is made lower in height on the rigid arm side than on the magnetic head side.

Abstract: A core burying channel is formed on the outer side surface of an air bearing rail of a floating magnetic head floating on a magnetic disk by an air-flow in a direction perpendicular to a magnetic recording medium travelling direction, and a magnetic core is buried in this core burying channel. This magnetic head can be produced easily by a production method which forms a core burying channel in a non-magnetic block, then deposits a magnetic material to the core burying channel and removes unnecessary portions of the magnetic material.

Abstract: A suspension mount apparatus for a transducer used in a magnetic memory for recording and reproduction, is characterized in that the points, at which a rigid arm and a magnetic head/arm assembly supported by the rigid arm are connected to each other, are provided within a region in which the rigidity of the connecting points vary at constant rates with respect to the distances between the connecting points and the borderlines between the rigid arm and the assembly.

Abstract: An improved magnetic head support mechanism intended for causing a magnetic head to float over a magnetic recording medium, comprises a spring member for retaining the magnetic head and a loading beam member provided with flanged portions along both longitudinal sides thereof and connected to the spring member at one end thereof and coupled to a shifting mechanism at the other end thereof and capable of giving the magnetic head an urging force to act on the magnetic recording medium. The loading beam member is penetratingly formed with at least one passing hole which permits the passing therethrough of an air stream generated by the rotational movements of the magnetic recording medium when the magnetic head is floating, so that it is possible to reduce the exciting force acting on the loading beam member and to thereby obtain the stabilized floating of the magnetic head.

Abstract: A slider equipped with a magnetic head is pressed on a magnetic disk surface under a constant pressure by a pressing member. The slider is loaded and unloaded by a loading/unloading mechanism. A driving unit of the loading/unloading mechanism has a shape memory alloy member which offers a shape memory effect based on the thermoelastic martensitic transformation, and a resilient member having a resilient force against the driving force of the shape memory alloy member. Moreover, the loading/unloading mechanism is arranged such that when the slide is loaded, the driving force of the loading/unloading mechanism is not applied to the pressing member supporting the slider.