The subject of the present invention is a method for communicating a malfunction of a system for measuring speed and direction of rotation of a rotary shaft, said system comprising: a toothed wheel associated with said rotary shaft, called target (14), a magnetic field sensor (10′), measuring values (K, A) of the magnetic field (B, B′, B″) generated by the passage of the teeth (T1, T2 . . . Ti) in front of said sensor (10′) and delivering a signal (S, S′, S″) to processing means 13). According to the invention, the method comprises the following steps: step 1: comparison by the sensor between the measured values and predetermined threshold values of the magnetic field, step 2: if the measured values are below the predetermined threshold values, step 3: generation by the sensor of a coding on the signal, representative of the measured values, to communicate a malfunction of the system to the processing means.

A magnetism detecting element detects a leakage magnetism from a scale, on which a magnetic signal with a constant period is recorded, and a relative position between the scale and the magnetism detecting element is detected. The magnetism detecting elements are arranged, along a detection direction of the magnetic signal relative to the scale, in a pattern with a pitch of 1/2n (n is a prime number of 3 or more) of a wavelength λ′ of a signal output by the element. Furthermore, as the pattern for cancelling m odd-order harmonics, the m-th power of 2 magnetism detecting elements are arranged within a range in which a pitch distance L of the magnetism detecting element farthest in the detection direction is expressed by L=(λ′/2)×(1/3+1/5+1/7+ . . . 1/(2m+1)).

A magnetic field measuring device having a semiconductor body with a surface parallel to an x-y plane and having a magnet with a flat main extension surface parallel to the x-y plane, the direction of magnetization changes along the main extension surface due to at least two adjacent magnetic poles, the magnet being rotatable relative to the IC package about an axis of rotation extending in a z direction and the z direction being orthogonal to the x-y plane. An imaginary extension of the axis of rotation passes through the magnet. The semiconductor body has three magnetic field sensors spaced apart from one another on the surface, and each of the magnetic field sensors measures the same component of the magnetic field. All magnetic field sensors are located along the imaginary extension of the axis of rotation within the projection of the main extension surface.

A magnetic encoder structure according to an exemplary embodiment of the present invention includes: a back plate; and a magnet rubber which has a ring shape, and is vulcanized and attached to a rear surface of the back plate, in which the magnet rubber has a plurality of protruding portions which protrudes from an adhesive surface that is attached to the back plate, and groove portions which are formed between the protruding portions, and the protruding portions and the groove portions are repetitively disposed in a rotation direction of the magnet rubber.

A rotation detection device includes a first mold IC, a second mold IC, and a housing. The first mold IC and the second mold IC are each housed in a point-symmetrical position with respect to a reference point in the housing. The housing includes a connector having (i) a first terminal electrically connected to the first mold IC, (ii) a second terminal electrically connected to the second mold IC, and (iii) a GND terminal that is electrically connected to both of the first and second mold ICs. The connector is arranged at a position corresponding to the reference point on the housing.

A displacement detection unit includes first and second sensors, an object, and a calculation section. The object includes first and second regions disposed periodically in a first direction, and performs displacement relative to the first and second sensors in the first direction. The first and second sensors detect first and second magnetic field changes in accordance with the displacement of the object and output the detected first and second magnetic field change as first and second signals, respectively. The first and second signals have different phases. The calculation section performs a calculation of an amount of the displacement of the object in the first direction multiple times per one period corresponding to a time period in which the object performs the displacement by an amount of displacement equivalent to a total of a continuous pair of the first and second regions, on a basis of the first and second signals.

A rotation angle sensor for detecting an absolute rotation angle upon single or multiple revolutions includes a magnetic field sensor and an encoder arrangement. The magnetic field sensor detects at least two orthogonal magnetic field variables. The encoder arrangement is rotatable depending on the absolute rotation angle relative to the magnetic field sensor, such that the magnetic field detected by the magnetic field sensor is dependent on a relative angular position of the encoder arrangement with respect to the magnetic field sensor. The encoder arrangement is furthermore displaceable relative to the magnetic field sensor. The relative angular position and the relative translational position of the encoder arrangement with respect to the magnetic field sensor is determined from the at least two orthogonal magnetic field variables. The absolute rotation angle is determined by means of the relative angular position and the relative translational position.

A relative rotational angular displacement detection device includes a pair of rotatable members rotatable relative to each other in a circumferential direction. A permanent magnet is attached to one of the rotatable members and includes magnetic poles magnetized in an axial direction of the axis of rotation and arranged to alternate in polarity in the circumferential direction. A magnetic flux guiding ring includes an annular ring body attached to the other of the rotatable members and is arranged coaxially with the axis of rotation, and a plurality of protruding portions each having a circumferential width smaller than the circumferential width of the magnetic pole. A magnetic detection unit is configured to detect magnetic fluxes of the ring body of the magnetic flux guiding ring. The magnetic flux guiding ring is magnetized depending on the positions of the protruding portions relative to the positions of the magnetic poles.

Embodiments relate to sensors, such as speed sensors and angle sensors, that use a modulated supply voltage to approximately double output signals of the sensors because the sensor element and the supply voltage exhibit the same frequency. In embodiments, the sensor element is an xMR element, and the modulated supply voltage is generated on-chip, such as by another xMR element. Direct frequency doubling of the output signal of the sensor element therefore can be obtained without additional and complex circuitry or signal processing.

An embodiment relates to a sensing magnet assembly and a motor including the same, the sensing magnet assembly comprising: a sensing plate; a sensing magnet disposed on the plate; and an adhesive tape disposed between the sensing plate and the sensing magnet so as to fix the sensing magnet to the sensing plate, wherein the sensing plate includes a main body in which the adhesive tape is disposed, the main body includes a seating surface and a plurality of grooves or holes, and one side of the adhesive tape is disposed on the seating surface. Accordingly, the adhesive strength between the sensing magnet and the sensing plate can be improved.