Abstract: The present invention provides a magnetic memory device based on a novel driving method realizing reliable writing and a method of writing the magnetic memory device. Four parallel portions are formed in a pair of loop-shaped write lines (6Xn) and (6Yn). Magnetoresistive devices (12A) and (12B) disposed in the parallel portion in an upper stage construct a memory cell (12Ev), and magnetoresistive devices (12A) and (12B) disposed in the parallel portion in a lower stage construct a memory cell (120d). When current in the direction from the drive point A to the drive point B is passed from the current drives (123n) and (133n), the directions of the currents in the write lines (6Xn) and (6Yn) are aligned in the parallel portion of the memory cell (12Ev) but are opposite to each other in the parallel portion in the memory cell (120d).

Abstract: A magnetic storage cell being capable of stable writing and having little adverse influence on an adjacent magnetic storage cell, and a magnetic memory device using the magnetic storage cell, and its manufacturing method are provided. In the invention, a plurality of TMR devices (1a) (1b) each including a TMR film (S20) including a connecting portion (14) of which the magnetization direction is changed by an external magnetic field and a second magnetic layer (8) and allowing a current to flow therethrough in a direction perpendicular to a laminate surface, and a toroidal magnetic layer (4) disposed on a surface of the TMR film (S20) so that a direction along the laminate surface is an axial direction and a write bit line (5) and a write word line (6) penetrate through the toroidal magnetic layer (4) are included, and the TMR devices (1a), (1b) share a part of the toroidal magnetic layer (4) between them.

Abstract: Each of a plurality of memory areas 3 provided in a magnetic memory 1 includes a TMR (tunneling magnetoresistive) element 4 having a first magnetic layer 41 of which magnetization direction A is changed by an external magnetic field; write wiring 31 for supplying the external magnetic field to the first magnetic layer 41 by means of a write current; a magnetic yoke 5 disposed so as to surround the periphery of the write wiring 31, being formed of an approximate ring shape having a pair of end faces 5a disposed face-to-face with a gap intervening therebetween; and a write transistor 32 for controlling conduction of the write current. The TMR element 4 is disposed so that a pair of side faces 4a thereof is positioned face-to-face to the pair of end faces 5a of the magnetic yoke 5.

Abstract: A magnetoresistive effect element includes a laminated body including a magnetosensitive layer a magnetizing direction of which is changed by an external magnetic field and constituted such that a current is made to flow in a direction orthogonal to a laminated layer face thereof, and a annular magnetic layer arranged at a side of one face of the laminated body to constitute an axial direction by a direction along the laminated layer face and constituted to be penetrated by a plurality of lead wires and therefore, a closed magnetic path can be formed by making current flow to a plurality of lead wires and inversion of magnetization at the magnetosensitive layer can further efficiently be carried out.

Abstract: A magnetic memory device includes a magneto-resistance effect element including a magnetic sensitive layer whose magnetization direction changes according to an external magnetic field; a write line to which a write current is supplied to apply an external magnetic field to the magnetic sensitive layer; and a write current drive circuit including a current direction control section for controlling the direction of the write current in the write line and a current amount control section for controlling the amount of the write current in the write line to a constant value.

Abstract: Each memory cell is constituted by a pair of magnetic memory elements. The magnetic memory elements are connected at one ends to sense bit lines, and at the other ends to a sense word line through a pair of reverse current preventing diodes, respectively. A constant current circuit is disposed on the grounded side of the sense word line. The constant current circuit has a function of fixing a current flowing through the sense word line, and is constituted by a constant voltage generating diode, a transistor and a current limiting resistor.

Abstract: Each memory cell is constituted by a pair of magnetic memory elements. The magnetic memory elements are connected at one ends to sense bit lines, and at the other ends to a sense word line through a pair of reverse current preventing diodes, respectively. A constant current circuit is disposed on the grounded side of the sense word line. The constant current circuit has a function of fixing a current flowing through the sense word line, and is constituted by a constant voltage generating diode, a transistor and a current limiting resistor.

Abstract: A magnetoresistive effect element includes a laminated body including a magnetosensitive layer a magnetizing direction of which is changed by an external magnetic field and constituted such that a current is made to flow in a direction orthogonal to a laminated layer face thereof, and a annular magnetic layer arranged at a side of one face of the laminated body to constitute an axial direction by a direction along the laminated layer face and constituted to be penetrated by a plurality of lead wires and therefore, a closed magnetic path can be formed by making current flow to a plurality of lead wires and inversion of magnetization at the magnetosensitive layer can further efficiently be carried out.

Abstract: A magnetic memory device includes a magneto-resistance effect element including a magnetic sensitive layer whose magnetization direction changes according to an external magnetic field; a write line to which a write current is supplied to apply an external magnetic field to the magnetic sensitive layer; and a write current drive circuit including a current direction control section for controlling the direction of the write current in the write line and a current amount control section for controlling the amount of the write current in the write line to a constant value.

Abstract: An actuator for precisely positioning an object to be positioned is fixed between the object and a support member. The actuator has a displacement generation part which includes a solid piezoelectric material member, a common electrode formed on one surface of the piezoelectric material member to cover substantially whole of the one surface, and first and second electrodes formed on the other surface opposite to the one surface, of the piezoelectric material member to superimpose to the common electrode. The first and second electrodes have side edges facing with each other via a uniform width space, respectively.

Abstract: An actuator for precisely positioning an object to be positioned is fixed between the object and a support member. The actuator has a displacement generation part which includes a solid piezoelectric material member, a common electrode formed on one surface of the piezoelectric material member to cover substantially whole of the one surface, and first and second electrodes formed on the other surface opposite to the one surface, of the piezoelectric material member to superimpose to the common electrode. The first and second electrodes have side edges facing with each other via a uniform width space, respectively.

Abstract: The present invention relates to an improvement in the write pole structure at a thin film magnetic head. At a write element, a gap film is provided between a first pole portion and a second pole portion. The first pole portion includes a second magnetic film adjacent the gap film and a first magnetic film adjacent the second magnetic film. The second pole portion includes a third magnetic film and a fourth magnetic film. The third magnetic film is provided adjacent to the gap film. The fourth magnetic film is provided adjacent to the third magnetic film. The surface of the fourth magnetic film facing opposite the medium is set within a width W21 of the third magnetic film in the direction of the tracks at its surface facing opposite the medium. In other words, the width W21 of the third magnetic film at the surface facing opposite the medium and a width W22 of the fourth magnetic film at its surface facing opposite the medium satisfy a relationship expressed as W22.ltoreq.W21.

Abstract: The present invention is directed to provide a magnetic head that is capable of effectively preventing TA noise.A slider 1 is provided with air bearing surfaces 111 and 121. Electromagnetic conversion elements 2 and 3, which are provided toward the trailing edge TR of the slider 1, perform electromagnetic conversion at the air bearing surfaces 111 and 121. The slider 1 is provided with indented portions 114 and projecting portions 115 at the air bearing surfaces 111 and 121 where the electromagnetic conversion elements 2 and 3 are provided. The indented portions 114 are provided in the areas corresponding to the width W2 of the electromagnetic conversion elements 2 and 3 viewed in the direction of the track width further toward the trailing edge TR than the electromagnetic conversion elements 2 and 3. The projecting portions 115 are provided adjacent to the indented portions 114 further projecting out compared to the indented portions 114.

Abstract: A thin film magnetic head includes a slider and thin film magnetic transducers, the slider supporting the thin film magnetic transducers. At least one of these thin film magnetic transducers is a magnetoresistive read element. The surface resistivity .rho. of the magnetic film of the magnetic disk is within the range of .rho..gtoreq.0.03.OMEGA..multidot.cm. Electric leak from the thin film magnetic head to the magnetic disk and electric discharge between these two are prevented.

Abstract: To perform digital processing of cyclical waveform signals that include random noise with high accuracy and high reliability without being practically affected by the noise. This is a waveform signal processor into which cyclical waveform signals are input and which outputs corresponding signals. It samples a cyclical waveform signal a plurality of times and then, based upon the obtained sampling values, it performs a Fourier Transform for all the various cycles. Next, the phase angle of a pre-selected frequency component in the Fourier series is determined based upon the Fourier Transform. Then a sampling point at the same phase for all cycles is specified by using the phase angle as a reference. The average of the sampling values at the same phase is calculated and output.

Abstract: In a magnetic recording and reproducing apparatus of a type wherein a magnetic disk having a magnetic recording layer formed on a rigid substrate is rotated at a high speed and magnetic recording and reproduction are conducted by the magnetic head disposed on the surface of the disk, the magnetic recording and reproducing apparatus being characterized in that the magnetic recording and reproducing are conducted by the magnetic head which is caused to fly from the magnetic disk at at least an area of the outermost cylinder of the magnetic disk and is caused to be substantially in contact with the surface of magnetic disk at at least an innermost cylinder of the magnetic disk.

Abstract: A magnetic recording disk comprising a rigid substrate and a magnetic layer of the continuous thin film type predominantly composed of .gamma.-Fe.sub.2 O.sub.3 shows high durability, especially CSS durability when the magnetic layer has specific peak area ratios in an X-ray diffraction chart thereof, the surface roughness of the substrate and medium surface is controlled to desired ranges, and a lubricating film of a perfluoro derivative of poly(n-propylene oxide) with a specific molecular weight is used. Reliable recording/reproduction can be conducted on the magnetic recording disk using a flying magnetic head.

Abstract: A magnetic recording medium comprising a glass substrate and a magnetic thin film thereon is provided for use in a magnetic recording/reproducing system having a flying magnetic head. Floating performance is improved when the glass substrate has a surface roughness Rmax of 10-80 A and the magnetic thin film has a surface roughness Rmax of 50-150 .ANG.. Recording and reproducing information on a magnetic disk is carried out by driving the magnetic disk while keeping a magnetic head floating relative to the disk at a spacing therebetween of up to 0.2 .mu.m.

Abstract: In a magnetic recording and reproducing apparatus of a type wherein a magnetic disk having a magnetic recording layer formed on a rigid substrate is rotated at a high speed and magnetic recording and reproduction are conducted by the magnetic head disposed on the surface of the disk, the magnetic recording and reproducing apparatus being characterized in that the magnetic recording layer constitutes an oxide layer, a nitride layer or an oxidized coating film at at least its surface layer, and the magnetic recording and reproducing are conducted by the magnetic head which is caused to be substantially in contact with the surface of magnetic disk at at least the innermost cylinder of the magnetic disk.

Abstract: A magnetic head comprises a slider which holds recording/writing elements at its medium opposing surface constituting a lifting force generating part and the surface area of the medium opposing surface is at most 2 mm.sup.2.A magnetic recording and reproducing apparatus has such magnetic head which is disposed on a magnetic disk having a magnetic recording layer formed on a rigid substrate while the disk is rotated at a high speed so that magnetic recording and reproducing are conducted between the magnetic head and the magnetic disk, wherein the surface roughness R.sub.max of the magnetic disk is at most 100 .ANG..