摘要:
A first detection unit has first and second detection circuits. A second detection unit has third and fourth detection circuits. Output signals of the second and fourth detection circuits differ from output signals of the first and third detection circuits in phase, respectively, by an odd number of times ¼ the signal period. The output signal of the third detection circuit differs from the output signal of the first detection circuit in phase by an integer multiple of ⅙ the signal period other than an integer multiple of ½ the signal period. A rotating field sensor generates a first signal based on the output signals of the first and third detection circuits, generates a second signal based on the output signals of the second and fourth detection circuits, and calculates a detected angle value based on the first and second signals.
摘要:
A rotation angle sensor includes a magnet that rotates about a rotation axis. The magnet has an end face perpendicular to the rotation axis and has a magnetization in a direction perpendicular to the rotation axis. The rotation angle sensor further includes a magnetic sensor that faces the end face of the magnet and detects a magnetic field produced by the magnet. The magnet includes a plate-shaped portion including the end face, and a ring-shaped portion that is located on a side of the plate-shaped portion farther from the end face and coupled to the plate-shaped portion. The plate-shaped portion does not include any hollow through which the rotation axis passes, whereas the ring-shaped portion includes a hollow through which the rotation axis passes.
摘要:
A field generation unit generates a rotating magnetic field including a first partial magnetic field in a first position and a second partial magnetic field in a second position. The first and second partial magnetic fields differ in direction by 180° and rotate in the same direction of rotation. A first detection unit detects, in the first position, a first angle that the direction of a first applied field forms with respect to a first direction. The first applied field includes the first partial magnetic field as its main component. A second detection unit detects, in the second position, a second angle that the direction of a second applied field forms with respect to a second direction. The second applied field includes the second partial magnetic field as its main component. A detected value of the angle that the direction of the rotating magnetic field in a reference position forms with respect to a reference direction is calculated based on detected values of the first and second angles.
摘要:
A rotating field sensor includes a first detection circuit that outputs a first signal indicating the intensity of a component of a rotating magnetic field in a first direction, a second detection circuit that outputs a second signal indicating the intensity of a component of the rotating magnetic field in a second direction, and an arithmetic circuit that calculates a detected angle value based on the first and second signals. Each of the first and second detection circuits includes at least one MR element row. Each MR element row is composed of a plurality of MR elements connected in series. Each MR element has a magnetization pinned layer. The plurality of MR elements forming each MR element row include one or more pairs of MR elements. Magnetization directions of the magnetization pinned layers in two MR elements making up a pair form a predetermined relative angle other than 0° and 180°.
摘要:
A field generation unit generates a rotating magnetic field including a first partial magnetic field in a first position and a second partial magnetic field in a second position. The first and second partial magnetic fields differ in direction by 180° and rotate in the same direction of rotation. A first detection unit located in the first position has first and second detection circuits whose output signals differ in phase by ¼ the period. A second detection unit located in the second position has third and fourth detection circuits whose output signals differ in phase by ¼ the period. A detected value of the angle that the direction of the rotating magnetic field in a reference position forms with respect to a reference direction is calculated based on a first signal generated from the output signals of the first and third detection circuits and a second signal generated from the output signals of the second and fourth detection circuits.
摘要:
A magnetic sensor for detecting a direction of an external magnetic field comprises: a bridge circuit configured to provide an output that changes in accordance with the direction of the external magnetic field, the bridge circuit including four resistance element sections, each of which comprises at least one magnetoresistance effect element; and two resistors connected to respective output terminals of the bridge circuit. The ratio of the resistance of each of the resistors to that of the bridge circuit is at least 2 when the resistance of each of the resistance element sections is at a minimum corresponding to a change in magnetoresistance.
摘要:
An angle detection unit including first to third arithmetic units receives first and second signals that are associated with intensities of components of a rotating magnetic field in mutually different directions. The first arithmetic unit generates a sum of squares signal made up of the sum of squares of the first and second signals. Based on the sum of squares signal, the second arithmetic unit calculates a first error component estimate which is an estimated value of a first error component included in the first signal and a second error component estimate which is an estimated value of a second error component included in the second signal. The third arithmetic unit generates a first corrected signal by subtracting the first error component estimate from the first signal, generates a second corrected signal by subtracting the second error component estimate from the second signal, and calculates a detected angle value based on the first and second corrected signals.
摘要:
A write shield layer that forms a part of a thin-film magnetic head is set with respect to the widthwise full length W thereof lying substantially on an air bearing surface that is opposite to the recording medium such that when the full length W is trisected, the maximum thickness H1/3side thereof in a range of widthwise ⅓ W size positioned at both ends thereof is larger than the average thickness Hm of the whole write shield layer from the air bearing surface up to the rear (H1/3side>Hm), so that the so-called external magnetic field resistance is improved, and inadvertent erasure of the information already recorded in the recording medium is avoided as much as possible. Besides, the PTP (pole tip protrusion) phenomenon arising from the generation of heat from coils, and external temperature changes can be held back.
摘要:
A magnetic sensor includes first to fourth MR elements. The first and second MR elements are connected at respective ends thereof through a first connecting portion in a central region. The third and fourth MR elements are connected at respective ends thereof through a second connecting portion that crosses the first connecting portion with a distance in a thickness direction in the central region. The first and fourth MR elements are connected at respective other ends thereof through a third connecting portion, and the second and third MR elements are connected at respective other ends thereof through a fourth connecting portion. Resistance values of the first and third MR elements change in a same increasing/decreasing direction, whereas resistance values of the second and fourth MR elements change in an increasing/decreasing direction opposite to the first and third MR elements, depending on an external signal magnetic field.
摘要:
The present invention provides a thin-film magnetic head which surely improves the writing and reading characteristic with reducing the flying height and surely handles the contact or collision with the magnetic recording medium.A thin-film magnetic head is provided, which includes, an substrate with ABS; a read or write head element provided on an element-formed surface of the substrate; at least one protrusion adjustment portion whose end reaches a slider end surface on the ABS side, which provides on an element-formed surface of the substrate; at least one heating portion provided rear at least one protrusion adjustment portion viewed from the slider end surface on the ABS side.