An apparatus, for determining a relative direction of a movement of an encoder object depending on a magnetic field which is generated or influenced by the encoder object. A magnetic field sensor generates two sensor signals based on the magnetic field, that indicate a profile of the magnetic field in the event of a relative movement between the encoder object and the magnetic field sensor, that fluctuate around a mean value and are phase-shifted 90° to one another. The processing circuit calculates an angle based on the two sensor signals, and determines the relative direction of the movement of the encoder object based on a gradient of the angle between a switch-on time of the apparatus and a threshold value angle which is reached thereafter or based on a gradient of the angle between the situation of two successive threshold value angles being reached.

A rotation detection device includes: a detector arranged with a gap to a rotating body in which rotation position information is periodically provided at regular intervals, and detecting a magnetic change as a rotation position of the rotating body; and a signal processor acquiring the rotation position information. The detector has first and second magnetic elements arranged with an interval of a/2 in a rotation direction. Each regular interval is defined as a. The first magnetic element outputs a first signal having a period corresponding to the regular intervals. The second magnetic element outputs a second signal having an opposite phase to the first signal and the period. The signal processor acquires a differential signal between the first and second signals as the rotation position information.

An encoder is provided that is capable of suppressing accuracy deterioration even if a scale is disposed in a tilted manner with respect to a receiving unit by being rotated around an axis (i.e., a rotation axis) orthogonal to a receiving surface. The encoder 1 includes scale 2 and detection head 3. The detection head 3 includes light source (transmitting unit) 4 and light-receiving unit (receiving unit) 5. The light-receiving unit includes light-receiving surface (receiving surface) 50 and converts light received at the light-receiving surface 50 into differential detection signals with two phases and outputs the same. The light-receiving surface 50 includes element array group 7 including four element arrays 71-74 provided in a parallel manner along an orthogonal direction, with each element array 71-74 including a plurality of light-receiving elements (receiving elements) 500. The plurality of element arrays 71-74 in the element array group 7 are disposed at positions where the sum of: (i) a distance in the orthogonal direction from a reference position to a positive phase signal element array 71, 72; and (ii) a distance in the orthogonal direction from the reference position to the negative phase signal element array 73, 74, is the same for all the phases of the at least two phases.

A rotation operation device using magnetic force, which is compact and enables a user to perform a proper operation. The rotation operation device includes a rotation operation member rotatable about a predetermined axis. A ring-shaped magnet is magnetized in a magnetization direction parallel to the predetermined axis such that magnetic poles alternate. The magnet rotates about the predetermined axis along with rotation of the rotation operation member. A first magnetic body have first tooth portions formed at predetermined intervals along a circumferential direction and extending in radial directions of the magnet. The magnet overlaps with the first tooth portions in a direction of the predetermined axis. An operating physical force is generated according to changes in positions of the magnetic poles and the first tooth portions, which are caused by rotation of the magnet.

A rotation detection device includes: a detector arranged with a gap to a rotating body in which rotation position information is periodically provided at regular intervals, and detecting a magnetic change as a rotation position of the rotating body; and a signal processor acquiring the rotation position information. The detector has first and second magnetic elements arranged with an interval of a/2 in a rotation direction. Each regular interval is defined as a. The first magnetic element outputs a first signal having a period corresponding to the regular intervals. The second magnetic element outputs a second signal having an opposite phase to the first signal and the period. The signal processor acquires a differential signal between the first and second signals as the rotation position information.

An apparatus and a method provide an output signal indicative of a speed of rotation and/or a direction of movement of a ferromagnetic object. The sensor includes at least one magnetic field sensing element configured to generate a magnetic field signal in response to a magnetic field associated with an object. The sensor includes a detector configured to generate a detector signal having edges occurring in response to a comparison of the magnetic field signal and the threshold signal. The sensor includes an output circuit configured to generate an output signal having a first format when a characteristic of the magnetic field signal is within a first range and having a second format different than the first format when the characteristic of the magnetic field signal is within a second range, different than the first range.

Wireless transmission of wheel rotation direction is disclosed. A disclosed apparatus includes a tone ring exhibiting a rotational asymmetry and a detector to measure a rotational direction of a wheel of a vehicle based on the rotational asymmetry and to measure a rotational speed of the wheel, where the detector or the tone ring is operatively coupled to the wheel. The disclosed apparatus also includes a wireless transmitter to transmit the rotational direction and the rotational speed to a receiver proximate or within an engine compartment of the vehicle.

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 method for diagnosing an inversion of a crankshaft sensor includes the following steps: acquiring a signal by way of the crankshaft sensor, at each detection of a tooth, determining a tooth time elapsed since the previous tooth detection, at each detection of a tooth, calculating a ratio Ri of the tooth times according to the formula Ri=(Ti−1).sup.2/(Ti*Ti−2), where Ri is the ratio, Ti is the last tooth time, Ti−1 is the penultimate tooth time, and Ti−2 is the tooth time preceding the penultimate tooth time, comparing the ratio Ri with a low threshold Sb, indicative of a turn marker, and a high threshold Sh, indicative of an absence of inversion, a ratio Ri between the two thresholds Sb, Sh being indicative of an inversion.

The invention relates to a counting sensor for counting the number of revolutions or of linear displacements of an object, wherein the counting sensor comprises: one single Wiegand module; at least one sensor element; a processing electronics connected to the sensor element; and a permanent magnet arrangement, which is movable relative to the Wiegand module; wherein the processing electronics is configured to obtain (i) direction informations indicating whether the permanent magnet arrangement moves in one direction or an opposite direction, and (ii) magnetic pole informations; and a data storage for storing a value, which indicates the number of the revolutions or of the linear displacements; wherein the processing electronics is configured: (i) to determine, on the basis of the direction information and the magnetic pole information, the number of the revolutions or of the linear displacements of the object and to store the corresponding value in the data storage, (ii) to perform, on the basis of a sequence of the direction informations and the magnetic pole informations, an error detection indicating whether one of the revolutions or one of the linear displacements of the object has not been recognized partially or completely, and (iii) upon detection of the error, to determine a corresponding correction of said number and to correct said value.