Patent application number | Description | Published |
20080284421 | ROTATION ANGLE DETECTING DEVICE - A rotation angle detecting device includes a signal generator, a magnetic rotor and a rotation angle calculating unit that calculates a rotation angle θ of the rotor based on the output signals of the signal generator. The signal generator includes a magnetic rotor that has a permanent magnet and a shaft connectable with the rotating object and at least three magnetic sensor elements disposed in the magnetic field to generate a plurality of output signals when the rotor rotates. The rotation angle calculating unit calculates a first candidate of the rotation angle θ from a first pair of the three output signals, examines whether the first candidate of the rotation angle θ is normal or not and calculates a next candidate of the rotation angle θ from another pair of the three output signals if the first candidate of the rotation angle θ is not normal, examines whether the next candidate of the rotation angle θ is normal or not, repeats the above two steps until a next candidate of the rotation angle θ is judged normal, and outputs one of the first and next candidates of the rotation angle θ as a formal rotation angle if it is judged normal. | 11-20-2008 |
20090319120 | VEHICLE STEERING ANGLE SENSOR - A steering angle sensor includes a magnetized body coupled through a gear to a steering shaft so as to rotate with rotation of the steering shaft, a magnetic sensing device for detecting a magnetic field generated by the magnetized body, a signal processing device for detecting a direction of the magnetic field based on the detected magnetic field and for detecting a steering angle of the steering shaft based on the direction of the magnetic field, a correlation signal output sensor mounted on the vehicle to output a correlation signal correlated with the steering angle, and a signal check circuit for determining whether the steering angle is valid or invalid based on comparison between the steering angle and the correlation signal. | 12-24-2009 |
20090322320 | ROTATION ANGLE DETECTING DEVICE - A rotation angle detecting device includes a housing, a rotating shaft rotatably held by the housing, a driving gear fixed to the rotating shaft, a driven gear engaged with the driving gear, a magnetic field generating part fixed in the driven gear, having a permanent magnet, and configured to generate a magnetic field, a magnetic sensor element configured to detect a change in the magnetic field due to a rotational movement of the magnetic field generating part, and a signal processor configured to process a signal from the magnetic sensor element for detecting a rotation angle of the rotating shaft. Each of teeth of the driving gear has a first circumferential width, each of teeth of the driven gear has a second circumferential width, and the second circumferential width is greater than the first circumferential width. | 12-31-2009 |
20100033064 | ROTATION DETECTOR AND DIRECT-CURRENT MOTOR - A power supply unit superimposes alternating-current voltage on direct-current voltage and applies it to a motor. As a result, when the motor is rotated, a current containing an alternating-current component flows. Further, the motor includes a capacitor connected in parallel with one phase coil. Owing to this capacitor, the impedance of the motor circuit between brushes is varied according to the rotation of the motor. Variation in impedance appears as variation in the amplitude of the alternating-current component in motor current. A signal processing unit extracts an alternating-current component from the motor current detected by the current detection unit and generates a rotation pulse corresponding to variation in the amplitude. A rotation angle detection unit detects the rotation angle of the motor based on this rotation pulse. | 02-11-2010 |
20100289387 | Rotation detecting apparatus and direct current motor - A rotation detecting apparatus includes a direct-current motor, a power source part, an energization detecting part, and a rotation state detecting part. The direct-current motor is configured so that an inductance between a pair of brushes periodically changes in accordance with a rotation. The power source part applies a power source voltage between the pair of brushes. In the power source voltage, an alternating-current voltage is superimposed on a direct-current voltage. The energization detecting part detects an electric quantity related to the alternating-current voltage applied from the power source part to the direct-current motor. The rotation state detecting part detects at least one of a rotation angle, a rotation direction, and a rotation speed of the direct-current motor based on a change in an amplitude of an alternating-current component in the electric quantity detected by the energization detecting part. | 11-18-2010 |
20110178673 | WEIGHT DETECTION DEVICE FOR VEHICLE AND METHOD FOR DETECTING WEIGHT OF VEHICLE COMPONENT - A vehicle includes a wheel and a vehicle body connected with each other via a suspension having a spring. An oscillation detection unit detects an oscillation of the vehicle body in forward and backward directions. A resonance frequency detection unit detects a resonance frequency of the vehicle body according to a detection result of the oscillation detection unit. A weight determination unit determines a weight of the vehicle body according to the resonance frequency detected by the resonance frequency detection unit. | 07-21-2011 |
20120235673 | STROKE AMOUNT DETECTING DEVICE - A stroke amount detecting device includes a magnetism detecting unit, a first magnetic field generating unit and a second magnetic field generating unit. A magnetic pole of the first generating unit and a magnetic pole of the second generating unit, which are opposed to each other, have different polarities. A distance between a gap end of the first generating unit and a gap end of the second generating unit, which are located on a farther side of a rectilinear axis, is smaller than a distance between an open end of the first generating unit and an open end of the second generating unit, which are located on a closer side of the rectilinear axis. The magnetism detecting unit detects a stroke amount of an object based on a magnetic flux generated between the open end of the first generating unit and the open end of the second generating unit. | 09-20-2012 |
20130312539 | TORQUE SENSOR - A torque sensor includes: a torsion bar; a multi-pole magnet; a pair of yokes on an outside of the multi-pole magnet in a radial direction and providing a magnetic circuit in a magnetic field generated by the multi-pole magnet; and a pair of magnetic sensors arranged along a circumferential direction. Each magnetic sensor includes a magnetism sensing part for detecting a magnetic flux density generated in the magnetic circuit, and outputs a detection signal to an external computing device. The magnetic sensors output the detection signals to the external computing device such that the computing device calculates a sum of outputs or a difference of outputs of the magnetic sensors so as to cancel a variation of the outputs produced by a magnetic flux generated from the multi-pole magnet and directly reaching the magnetism sensing parts. | 11-28-2013 |