Abstract: A full bridge circuit comprises first to fourth magnetic resistance elements. The first and fourth magnetic resistance elements have a first polarity, while the second and third magnetic resistance elements have a second polarity. A comparison circuit compares a first value indicating a difference between a potential of a first connecting node and a first potential and a second value indicating a difference between a potential of a second connecting node and a second potential to determine presence/absence of an external magnetic field. An initial magnetization vector of a magnetization free layer of the first magnetic resistance element is the reverse of that of a magnetization free layer of the second magnetic resistance element. An initial magnetization vector of a magnetization free layer of the third magnetic resistance element is the reverse of that of a magnetization free layer of the fourth magnetic resistance element.

Abstract: A current sensor comprises: a plurality of magnetoresistance elements whose resistance value changes by application of an current-induced magnetic field from a current-to-be-measured; and a selection circuit that selects one magnetoresistance element from these plurality of magnetoresistance elements and outputs a signal of a selected magnetoresistance element. In the plurality of magnetoresistance elements, relationships between a magnitude of the applied current-induced magnetic field and the resistance value are different from each other.

Abstract: A current sensor comprises a plurality of magneotresistance elements and a first magnetic body. The plurality of magneotresistance elements each have their resistance value change by being applied with an current-induced magnetic field from a current to be measured. The first magnetic body applies a first offset magnetic field substantially parallel to the current-induced magnetic field applied to a first magneotresistance element of the plurality of magneotresistance elements. Moreover, a smart meter according to an embodiment of the present invention has, for example, the current sensor according to the present embodiment installed therein.

Abstract: According to one embodiment, a sensor includes a supporter, a film portion, a first sensing element, a second sensing element, and a processor. The film portion is supported by the supporter, and is deformable. The first sensing element is fixed to the supporter, and Includes a first magnetic layer, a second magnetic layer, and a first intermediate layer provided between the first magnetic layer and the second magnetic layer. The second sensing element is fixed to the film portion, and includes a third magnetic layer, a fourth magnetic layer, and a second intermediate layer provided between the third magnetic layer and the fourth magnetic layer. The processor outputs an output signal when a first signal is in a first state. The first signal is obtained from the first sensing element. The output signal is based on a second signal obtained from the second sensing element.

Abstract: According to one embodiment, a printed wiring board includes a first magnetic layer, a second magnetic layer, an insulating layer, a first conductor layer, and a second conductor layer. The insulating layer is provided between the first magnetic layer and the second magnetic layer. The first conductor layer is provided between the insulating layer and the first magnetic layer. The second conductor layer is provided between the insulating layer and the second magnetic layer.

Abstract: A full bridge circuit comprises first to fourth magnetic resistance elements. The first and fourth magnetic resistance elements have a first polarity, while the second and third magnetic resistance elements have a second polarity. A comparison circuit compares a first value indicating a difference between a potential of a first connecting node and a first potential and a second value indicating a difference between a potential of a second connecting node and a second potential to determine presence/absence of an external magnetic field. An initial magnetization vector of a magnetization free layer of the first magnetic resistance element is the reverse of that of a magnetization free layer of the second magnetic resistance element. An initial magnetization vector of a magnetization free layer of the third magnetic resistance element is the reverse of that of a magnetization free layer of the fourth magnetic resistance element.

Abstract: A current sensor comprises a plurality of magnetoresistance elements and a first magnetic body. The plurality of magnetoresistance elements each have their resistance value change by being applied with an current-induced magnetic field from a current to be measured. The first magnetic body applies a first offset magnetic field substantially parallel to the current-induced magnetic field applied to a first magnetoresistance element of the plurality of magnetoresistance elements. Moreover, a smart meter according to an embodiment of the present invention has, for example, the current sensor according to the present embodiment installed therein.

Abstract: A current sensor comprises: a plurality of magnetoresistance elements whose resistance value changes by application of an current-induced magnetic field from a current-to-be-measured; and a selection circuit that selects one magnetoresistance element from these plurality of magnetoresistance elements and outputs a signal of a selected magnetoresistance element. In the plurality of magnetoresistance elements, relationships between a magnitude of the applied current-induced magnetic field and the resistance value are different from each other.

Abstract: An elastic modulus according to the present embodiment includes a light source configured to generate light having a wavelength at which a material within a measurement target absorbs the light. An optical system causes the light to be passed through the measurement target at a desired aperture diameter and focuses the light on the material. A detector contacts the measurement target and detects an acoustic wave generated when the material absorbs the light. An operation unit calculates an elastic modulus of the material using a first acoustic-wave measurement value obtained in a case where the aperture diameter is a first diameter and a second acoustic-wave measurement value obtained in a case where the aperture diameter is a second diameter different from the first diameter.

Abstract: According to one embodiment, a magnetic storage medium, includes a magnetic recording layer that includes: a servo area including predetermined servo information; a user data area including predetermined user information; two preamble areas including a plurality of magnetic bodies made of magnetic particles, the magnetic bodies being arranged in a staggered pattern so that the staggered pattern is inverted with respect to an axis of symmetry at a track center; and a re-sync mark area positioned at a head of the preamble areas and indicates a start of the preamble areas.

Abstract: According to one embodiment, a method of detecting contact of a magnetic head with a magnetic disk by changing the dynamic flying height of the magnetic head in a magnetic disk drive is disclosed. The method can change control of a spindle motor configured to rotate the magnetic disk, from feedback control to open loop control. The method can detect a change in rotational speed of the magnetic disk during the open loop control. The method can detect contact of the magnetic head with the magnetic disk based on the detected change in the rotational speed.

Abstract: According to one embodiment, a method of detecting contact of a magnetic head with a magnetic disk by changing the dynamic flying height of the magnetic head in a magnetic disk drive is disclosed. The method can change control of a spindle motor configured to rotate the magnetic disk, from feedback control to open loop control. The method can detect a change in rotational speed of the magnetic disk during the open loop control. The method can detect contact of the magnetic head with the magnetic disk based on the detected change in the rotational speed.

Abstract: According to one embodiment, a magnetic recording medium to which a signal is recorded by reversing magnetization of a magnetic body, includes: a servo region to which a servo signal is written; a data region configured to include a magnetic region of a track to which data is written, the magnetic region being separated from other magnetic region of other track; and a periodic magnetic pattern region configured to be provided at a head portion of the data region following the servo region, and is inclined at a predetermined angle with respect to a circumferential direction of the magnetic recording medium, over a predetermined length in a radius direction of the magnetic recording medium.

Abstract: A magnetic storage medium includes: burst lines each including magnetic bodies placed in a nonmagnetic body in a predetermined repetitive pattern repeated in the radial direction, the burst lines arranged in the circumferential direction at predetermined intervals, wherein the phases of the predetermined repetitive patterns are shifted in the radial direction relative to a circumferential line at least between the adjacent ones of the burst lines.

Abstract: A storage apparatus includes a magnetic storage medium which is formed with a data portion based on isolated magnetic dots and a servo pattern portion, a drive mechanism which drives the storage medium, a head actuator which includes a head for reading and writing data from and to the storage medium, and a permanent magnet which is disposed at a position that is opposable to a whole radial region of the servo pattern portion, during a rotation of the storage medium.

Abstract: According to one embodiment, a method of detecting contact of a magnetic head with a magnetic disk by changing the dynamic flying height of the magnetic head in a magnetic disk drive is disclosed. The method can detect a change in the rotational speed of the magnetic disk. The method can detect the contact of the magnetic head with the magnetic disk based on the detected change in the rotational speed.

Abstract: According to one embodiment, a magnetic storage medium, includes a magnetic recording layer that includes: a servo area including predetermined servo information; a user data area including predetermined user information; two preamble areas including a plurality of magnetic bodies made of magnetic particles, the magnetic bodies being arranged in a staggered pattern so that the staggered pattern is inverted with respect to an axis of symmetry at a track center; and a re-sync mark area positioned at a head of the preamble areas and indicates a start of the preamble areas.

Abstract: According to one embodiment, a magnetic recording medium to which a signal is recorded by reversing magnetization of a magnetic body, includes: a servo region to which a servo signal is written; a data region configured to include a magnetic region of a track to which data is written, the magnetic region being separated from other magnetic region of other track; and a periodic magnetic pattern region configured to be provided at a head portion of the data region following the servo region, and is inclined at a predetermined angle with respect to a circumferential direction of the magnetic recording medium, over a predetermined length in a radius direction of the magnetic recording medium.

Abstract: According to one embodiment, a magnetic storage apparatus includes a magnetic storage medium that includes a servo pattern in which magnetic bodies magnetized to one of an S-pole and an N-pole are discretely arranged in a non-magnetic substance at least in a recording track line direction, an electromagnetic conversion element configured to output a reproduction signal according to a magnetic field leaking from the magnetic bodies; a rectifier circuit configured to receive the reproduction signal swinging from positive to negative and vice versa corresponding to a magnetic pole, and generate a reproduction signal swinging to either a positive or negative direction according to the reproduction signal; and a control circuit configured to cause the electromagnetic conversion element to be positioned to a single recording track on the magnetic storage medium according to the reproduction signal generated in the rectifier circuit.

Abstract: A magnetic storage medium includes: burst lines each including magnetic bodies placed in a nonmagnetic body in a predetermined repetitive pattern repeated in the radial direction, the burst lines arranged in the circumferential direction at predetermined intervals, wherein the phases of the predetermined repetitive patterns are shifted in the radial direction relative to a circumferential line at least between the adjacent ones of the burst lines.