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.

A positioning apparatus includes a sensor assembly, a moving member, and a detecting plate. The sensor assembly includes a sensor positioning and detecting assembly and a sensor location recognition assembly. The sensor assembly is mounted on the moving member, and the moving member drives the sensor assembly to move on the detecting plate. The sensor assembly moves on the detecting plate, the sensor location recognition assembly recognizes that the sensor assembly reaches a designated location, and the sensor assembly is positioned by the sensor positioning and detecting assembly. The positioning apparatus and the card issuing machine provided by the application avoid the phenomena of step lost and speed reduced, and the location of the sensor assembly can be monitored in real time through the detecting plate.

An absolute position readout apparatus includes an encoder device and a readout device. The readout device includes multiple first and second magnetic sensing components that correspond to an absolute track of the encoder device, and a third magnetic sensing component and a fourth magnetic sensing components that correspond to an incremental track of the encoder device. The third magnetic sensing component is configured to be spaced apart from the fourth magnetic sensing component by a specific distance, so as to prevent misreading of absolute position information from the first or second magnetic sensing components being at positions corresponding to boundaries between adjacent magnetized regions of the absolute track.

An encoder includes: a reading device that reads respective electric signals from two incremental patterns respectively having graduation array pitches different from each other; a control device that calculates a measurement value, based on the electric signals; and an output device that outputs the measurement value. The control device includes: an absolute position synthesis unit that synthesizes two electric signals to generate a synthesized absolute position; a detection unit that detects two relative positions from the two electric signals; a position calculation unit that performs an arithmetic operation between the relative positions and the synthesized absolute position to calculate a calculated absolute position; an absolute position comparison unit that compares the calculated absolute position with the synthesized absolute position; and a relative position comparison unit that compares the two relative positions with each other. The output device outputs error information, based on a comparison result output from the control device.

Systems are described for converting the angular position of a shaft or an axle of a rotary motor to an analog or a digital code indicative of the angular position. The systems may include a magnetic disk encoded with first magnetic transitions and second magnetic transitions, where the first magnetic transitions are on a first circumference of the magnetic disk, the second magnetic transitions are on a second circumference of the magnetic disk, the first magnetic transitions represent regions on the magnetic disk, and the second magnetic transitions represent locations on the magnetic disk within each of the regions. The systems may include a first sensor to detect a region based on the first magnetic transitions and a second sensor to detect a location based on the second magnetic transitions. The systems may also include a decoder to identify an absolute location on the magnetic disk based on the region detected by the first sensor and the location detected by the second sensor.

A rotation angle measuring apparatus and method are provided for measuring a rotation angle of a moving disk relative to a stationary disk, the moving disk being configured to rotate about an axis and the stationary disk being arranged opposite the moving disk. A magnet is arranged on the moving disk. A first magnetic sensor is arranged on the stationary disk, the first magnetic sensor generating an angle signal under the action of the magnet as the moving disk rotates. An incremental rotation angle of the moving disk is determined on the basis of an output of the receiving region, a period of the static electric field is determined on the basis of an angle signal generated by the first magnetic sensor, and an absolute rotation angle of the moving disk is determined on the basis of the period of the static electric field and the incremental rotation angle.

A hollow type rotation detecting device has a 2-pole magnet ring and a multi-pole gear, the 2-pole magnet being coaxially fixed to the outer circumferential surface of the shaft end part of a hollow motor shaft that extends coaxially inside a cylindrical cover. In an annular gap between the cylindrical cover and the 2-pole magnet ring and multi-pole gear, rigid boards are arranged with an orientation facing in a tangential direction at prescribed intervals along the circumferential direction. The rigid boards are electrically connected to one another by flexible printed wiring boards. It is possible to obtain a rotation detecting device suitable to be incorporated into the narrow annular gap between a motor house and the shaft end part of the hollow motor shaft in a hollow motor having a large hollow diameter.

A system for determining an absolute position of a device includes a high resolution track (14), a sensor and processing unit (22) associated with the high resolution track (14), a reference track (18) having a plurality of pole pairs arranged to define a single-track Gray code segment, and an array of Hall effect sensors (26) associated with the reference track to output a reference signal to the sensor and processing unit indicative of the coarse absolute position of the device over the single-track Gray code segment. The sensor and processing unit (22) combines the reference signal with the position of the device over the high resolution track to determine an initial, fine absolute position of the device. An up/down hardware counter (34) increments the initial fine absolute position using a signal generated from the high resolution track, and without any further software-based processing, to maintain and continuously update the fine absolute position of the device.

A vernier sensor including a coarse sensor and a fine sensor may require calibration to ensure accurate position measurements. Calibration may include determining coefficients for harmonics that can be added to the coarse sensor output and the fine sensor output to reduce harmonic distortion. The disclosure describes using the offset and variance of a difference signal as the basis for calibration. This approach is possible at least because the frequencies of the coarse sensor and fine sensor can be selected to reduce the complexity of these calculations.

A position detection device includes a motor that rotates a drive target, a periodic sensor that detects a plurality of periods included in a periodic change generated by rotation of the motor, an origin sensor that detects an origin of the motor in a rotation direction, and a controller that controls the rotation of the motor based on signals output from each of the periodic sensor and the origin sensor. A repeated detection error in detecting the origin by the origin sensor is smaller than a rotation range of the motor corresponding to each period of the plurality of periods detected by the periodic sensor.