Provided is an encoder that can sense an abnormality in the attitude of a detector with respect to a scale. An encoder includes a scale and a detector, the scale being provided on one measurement target part with marks arranged on the scale, and the detector being provided on another measurement target part and configured to detect an amount of relative movement with the scale. The scale includes a sensing unit that senses the attitude of the detector with respect to the scale, and thus even in a case where an abnormality in the attitude of the detector with respect to the scale cannot be sensed on the basis of a change in a signal read by a reading unit, the abnormality can nevertheless be sensed.

A motor control device includes: a polarity sensor configured to detect whether a magnetic pole position in a synchronous motor resides on a positive polarity side or a negative polarity side with reference to a reference position; a motor control unit configured to turn the synchronous motor from the polarity side detected by the polarity sensor toward an opposite polarity side through the reference position; and a magnetic pole position determination unit configured to determine, as the magnetic pole position, a position of the synchronous motor at the moment when the polarity changes, based on a detection result of the polarity sensor.

There is provided an optical encoder with alignable relative positions between elements including an encoding medium, a sensor package and a memory. The sensor package includes a photodiode array and two alignment photodiodes opposite to the encoding medium. The memory records an alignment pattern associated with output signals of the two alignment photodiodes when the encoding medium and the sensor package are at nominal operating positions. When the encoding medium and the sensor package are not at the nominal operating positions, the relative position alignment is performed by adjusting current relative positions between the encoding medium and the sensor package to cause a current pattern associated with output signals of the two alignment photodiodes to be identical to the alignment pattern.

An encoder includes a code disc and a processor communicatively coupled with the code disc. The code disc is configured to rotate along with a rotating object and includes a plurality of fan teeth extending radially. Each of the fan teeth includes a first line segment, a second line segment, and an arc edge along a circumference of the code disc and connecting the first line segment and the second line segment. The first line segment edges of the fan teeth are arranged at the code disc with equal intervals. A length of the arc edge of one of the fan teeth is different from lengths of other ones of the fan teeth, and the lengths of the other ones of the fan teeth equal each other. The processor is configured to detect a rotation of the code disc to obtain a detection signal, and obtain a rotation parameter of the rotating object based on the detection signal. The rotation parameter includes at least one of a rotation direction, a rotation speed, or a mechanical zero position.

Disclosed embodiments include a two-dimensional scale with a simple arrangement capable of omitting setting of an origin mark in the Y-axis direction. In a linear scale, a reference origin mark array and a tilting origin mark array that is a tilting marker array are provided in an origin mark region. Since the reference origin mark array is parallel to X-coordinates, an X-direction origin signal is correctly generated. On the other hand, for the Y direction in which no origin mark is provided, the distance between a reference origin mark and a tilting origin mark is detected. A Y-direction absolute position is decided in accordance with the distance.

Provided is an encoder device capable of reducing interference between a magnetic field generated in a reference mark and a magnetic field generated in a scale. An encoder device is provided with a reference mark and a head. The reference mark has: a first scale coil; and a second scale coil electrically connected to the first scale coil. The head has: a transmission coil that transmits an electromagnetic wave without any contact to the first scale coil; a reception coil that receives an electromagnetic wave without any contact from the second scale coil; and electric circuits that generate a pulse for generating an origin signal from the electromagnetic wave received by the reception coil, if the transmission coil faces the first scale coil and the reception coil faces the second scale coil.

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.

An internal combustion engine includes a crankshaft that has a journal linked to a bearing and is rotatably supported on the crankcase, a power transmission gear fixed to an extremity of the crankshaft that has a smaller diameter than a diameter of the journal and projects outward of the crankcase, a to-be-detected body that is fixed on an outer periphery of a collar member disposed between the bearing and the power transmission gear and is relatively non-rotatably supported on the crankshaft, and a detection sensor that is made to face a trajectory of the to-be-detected body and detects movement of the to-be-detected body to generate a pulse signal. This provides a structure for disposing a to-be-detected body that enables any increase in the dimensions of an internal combustion engine to be avoided.

A measuring device for a spindle or for a rotary table includes at least two first and second position sensing elements and a scale element, having a first and second graduations and being rotatable about an axis of rotation relative to the position sensing elements. The first graduation includes regular structures arranged in parallel next to one another along a first direction, having a directional component in the circumferential direction. The second graduation includes regular structures arranged in parallel next to one another along a second direction, having a directional component in the axial direction. The first position sensing elements are offset from one another in the circumferential direction, and are able to scan the first graduation so that the position of the scale element in a plane having an orthogonal orientation to the axis of rotation is determinable. In addition, at least one of the first position sensing elements is able to determine an angular position of the scale element in relation to the first position sensing elements in absolute terms within and across a rotation. The second position sensing elements are offset from one another in the circumferential direction, and are able to scan the second graduation, and the axial position of the scale element is able to be determined.

A position-measuring device includes a carrier body having a first and second measuring graduations and a reference mark. The first and second measuring graduations include graduation structures periodically arranged along first and second measurement directions, respectively, that are perpendicular to each other. The graduation structures of the first measuring graduation each extend parallel to a first direction and the reference mark extends in a second direction that forms an angle different from 0 with the first direction. First and second scanners are configured to scan the first and second measuring graduations and generate first and second scanning signals, respectively. A third scanner is configured to scan the reference mark and generate a reference pulse. The position-measuring device is configured such that a phase angle of the reference pulse is determined as a function of the first scanning signals and the reference pulse.