In a magnetic field source detecting apparatus, a magnetic sensor unit detects an intensity and a direction of a measurement target magnetic field on or over a surface of a test target object; and a position estimating unit estimates a position in a depth direction of a magnetic field source that exists at an unspecified position inside a test target object on the basis of the intensities and the directions of the measurement target magnetic field detected by the magnetic sensor at at least two 2-dimensional positions of the surface.

According to an embodiment, a blade driving device in which a central axis is defined includes a plurality of blades and a plurality of groups. The blades are arranged around the central axis. Each of the groups has a magnet and at least two coils and the groups are arranged at intervals along a circumference of a circle centered on the central axis. A winding axis direction of the coil coincides with a normal direction of a facing surface of the magnet facing the coil, magnetic poles formed on the facing surface are reversed at a position corresponding to a center of the coil when viewed from the winding axis direction, and each of the groups generates an electromagnetic force along a circumference direction of the circle to drive the blades.

The present disclosure discloses a display panel and a detecting method thereof. By providing at least one resistance sensor in a bending region, an extending direction of the resistance sensor is perpendicular to an extending direction of an axis for bending and overlaps with the axis for bending. By electrically connecting the resistance sensor to a detecting circuit, a change of the resistance value of the resistance sensor can be reflected as a change of voltage.

A localization and attitude estimation method using magnetic fields includes the following steps. First, in three-dimensional coordinates, at least three magnetic landmarks arbitrarily disposed around a moving carrier are selected, wherein any two of the at least three magnetic landmarks have different magnetic directions. One set of at least five tri-axes magnetic sensors is used to sense the magnetic fields of the at least three magnetic landmarks. Three magnetic components on three axes of a current position of each of the tri-axes magnetic sensors are respectively generated by a demagnetization method. Five non-linear magnetic equations are solved to obtain position information and magnetic moment information of the at least three magnetic landmarks in the three-dimensional coordinates. Position vectors and attitude vectors of the set of at least five tri-axes magnetic sensors in a three-dimensional space are estimated based on tri-axes magnetic moment vectors of the magnetic landmarks.

For an easily implementable method for position determination using an inductive position sensor with increased precision of the position information, the position sensor generates a measurement signal from which a frequency functional dependent on the excitation frequency is formed, which represents a measure of the noise signal and the excitation frequency of the excitation signal is changed so that the frequency functional is minimized or maximized and the excitation frequency that minimizes or maximizes the frequency functional is used for the excitation signal.

A position detection device includes a position sensor including a coil and a magnetic core, and a signal processor. The signal processor generates a rectangular wave voltage applied to the coil, converts a current which flow through the coil by the rectangular wave voltage into a voltage and outputs the voltage, and acquires a voltage measurement value obtained by sampling the output voltage after predetermined time in synchronization with a timing of rising or falling of a waveform of the rectangular wave voltage. The predetermined time is set such that the voltage measurement value is restricted within a range of 40% or more and 99.999% or less with respect to a maximum value of the rectangular wave voltage when the coil is at a position where an inductance of the coil is minimum.

A position detection apparatus includes a magnetic unit and a sensor. The magnetic unit includes a magnetic member and a retainer. The magnetic member includes a magnet and a first magnetic yoke. The magnet extends in an axial direction and has a cross-section orthogonal to the axial direction, and a first maximum outer diameter in a radial direction orthogonal to the axial direction. The cross-section has a substantially constant area in the axial direction. The first magnetic yoke is disposed adjacent to the magnet in the axial direction and has a second maximum outer diameter in the radial direction. The second maximum outer diameter is greater than the first maximum outer diameter. The retainer extends in the axial direction and retains the magnetic member. The sensor detects a magnetic field that changes in association with a movement of the magnetic unit along the axial direction.

The invention relates to an FFF printing system (100), the FFF printing system comprising a print head (105), a feeder (91;126) arranged to feed a filament (4) into the print head (105), and a container (801) for storing the filament on one or more filament spools (88). The system also comprises a prefeeder (81) arranged to feed the filament from the spools to the feeder (91;126), and a first flexible tube (D01;102;121) for guiding the filament (4). A filament path length measuring device (1) is arranged to detect a misalignment between the feeder and the prefeeder. Measurement signals are sent to a processing system to correct any misalignment.

A position sensor is configured to use a Wiegand wire, position magnet(s) and a reset magnet in which changes in polarization of the Wiegand wire caused by the position magnet(s) can be reset by the reset magnet. The position magnet(s), which can move in relation to the Wiegand wire, can have relatively stronger magnetic flux densities, and the reset magnet, which can be fixed in relation to the Wiegand wire, can have a relatively weaker magnetic flux density. When the position magnet(s) are proximal the Wiegand wire, the relatively stronger position magnet(s) overcome the reset magnet to cause a change in polarization of the Wiegand wire which produces an electrical pulse which can be counted. However, when the position magnet(s) become distal to the Wiegand wire, the relatively weaker reset magnet can reset the polarization of the Wiegand wire to prepare for a next count. As a result, the total number of magnets required in the system can be reduced, and the probability of failing to reset the Wiegand wire can be lowered.

Linear electric actuator (1) comprising a housing (10) with a reversible DC-motor (2), which through a transmission (3) can move an activation element (6) between two end positions, where an incremental position detection system is adapted to indicate the position of the spindle nut (5) during its travel on the spindle (4) and where the accuracy of the position detection system continuously is calibrated in that a magnet (15) is arranged in connection with the spindle nut (5), and at least one magnetic sensor (13,14) is arranged within the housing (10) of the actuator in a position where a proximity with the magnet (15) arranged in connection with the spindle nut (5) on its travel on the spindle (4) is achieved to establish a reference point for the position detection system.