A rotation detection apparatus includes a signal detector and a determination circuit. The signal detector outputs a first signal and a second signal based on changes in respective resistance values of magnetoresistive element pairs. The first signal has a waveform corresponding to convexities and concavities of a rotor, while the second signal has a waveform differing in phase from the first signal. Upon receiving the first signal and second signal, the determination circuit compares each of the first signal and second signal against a binarization threshold value to generate a first binarized signal and a second binarized signal. The determination circuit permits output of the first binarized signal during one of a concavity period and a convexity period of the second binarized signal, and prohibits output of the first binarized signal during the other one of the concavity period and convexity period.

The present invention provides an apparatus for sensing rotor location, the apparatus comprising: a central shaft; a magnet coupled to the central shaft; a sensor portion is disposed correspond to the magnet; wherein the sensor portion comprising a substrate, a first group including a first Hall sensor and a third Hall sensor disposed on the substrate, and a second group including a second Hall sensor and a fourth Hall sensor, the first Hall sensor and the third Hall sensor are arranged to overlap in a radial direction about the central shaft and the second Hall sensor and the fourth Hall sensor are arranged to overlap in a radial direction about the central shaft.

A position detection sensor includes: a linear member; a conductive portion and an insulating portion provided in an outer periphery of the linear member and arranged side by side in a direction of an axis of the linear member; a support member having insulating properties and provided so as to be capable of being relatively advanced or retracted in the direction of the axis with respect to the conductive portion and the insulating portion; and a conductive contact member attached to the support member and configured such that a distal end of the contact member comes in contact with outer surfaces of the conductive portion and the insulating portion by a biasing force toward the outer surfaces of the conductive portion and the insulating portion.

A rotation detection sensor is disposed to face an outer peripheral part of a signal rotor, and outputs a detection signal corresponding to a position of the outer peripheral part with the rotation of the signal rotor. The rotation detection sensor detects a rotation reference position with the detection of switching from projections to a missing tooth part on the basis of a gap to the signal rotor, and detects switching from the missing tooth part to the projections to output a rotation reference position signal indicative of position information on the rotation reference position at timing of the detection. An ECU receives the detection signal and the rotation reference position signal from the rotation detection sensor, and acquires the rotation reference position on the basis of the rotation reference position signal.

A current source sensor delivers detection information in the form of an intermediate signal by selectively applying a low-level or high-level current to a communication bus depending on the passage of a mobile target, the sensor including a sensitive portion detecting the passage of a of the mobile target, an electronic module controlling and shape signals coming from the sensitive portion, an embedded intelligence module designed, inter alia, to receive information from another sensor through a first signal present on the communication bus, the first signal being the sum of the abovementioned intermediate signal generated by the sensor and of another intermediate signal generated by the other sensor, wherein the embedded intelligence module is adapted to modify a first low level and a first high level of the intermediate signal, respectively, into a second low level and into a second high level depending on a the first signal.

A distance measuring device includes a deflecting mirror configured to reflect transmission waves, and a swing motor configured to swing the deflecting mirror round a swing shaft so that scanning with the transmission waves is performed within a predetermined scanning region. The swing motor is configured to swing the deflecting mirror within a range of a predetermined rotation angle from a reference position, which is a rotational position of the deflecting mirror that reflects the transmission waves in a direction to a substantial center of the scanning region. The deflecting mirror is configured to return to the reference position when a distance measuring process, in which scanning with the transmission waves is repeated, ends.

In a monitoring unit for monitoring position signals of incremental position-measuring devices, at least two position signals are applied on the input side that result from the scanning of an incremental graduation track by a scanning unit and that are out-of-phase with each other. The monitoring unit includes a signal logic unit with which at least two position-dependent status data words are able to be generated from different position signals, and an evaluation unit to which the status data words are supplied, in which invalid statuses are ascertainable by comparing the status data words, and an error signal is able to be generated in response to an ascertained invalid status.

A method for finding a reference correction value of an angular encoder index mark is given. The angular encoder has a first read head, a second read head, and a patterned element that includes incremental marks and an index mark. In a first instance, the first read head detects the presence of the index mark and, in response, the second read head generates a first analog signal. In a second instance, the first read head detects the presence of the index mark and, in response, the second read head generates a second analog signal. A processor determines the reference correction value based at least in part on the first analog signal and the second analog signal.

A rotation angle detection apparatus includes an incremental rotary scale and a detector. The rotary scale includes both a detection region having a scale formed therein for detecting a rotation angle of an object and a non-detection region having no scale formed therein. The detector generates, based on an input signal indicating change in the position of the scale of the detection region which changes according to change in the rotation angle of the object, an electrical signal that periodically changes according to the change in the position of the scale of the detection region. Further, the detector detects the rotation angle of the object based on the electrical signal. Furthermore, the detector detects a reference angle for the rotation angle of the object by counting the number of positional changes from an end of the scale of the detection region; the positional changes are indicated by the input signal.

A device for determining an angle of rotation and/or a torque of a rotating part, having at least one angle detector for detecting an angular position of the rotating part relative to a reference position and at least one indexer for indexing at a 360° rotation of the rotating part relative to the reference position, the angle detector having a rotor connected in a non-rotatable manner to the rotating part with a base body for attachment to the rotating part and a plurality of vanes extending radially outwardly from the base body. At least one of the vanes of the rotor have a marker detectable by means of the indexer.