An optical sensor for a delivery device having a piston that displaces a substance, such as a fluid, from a reservoir. The optical sensor has a light source and a detector array for imaging encoding features disposed along a plunger rod coupled to the piston. By virtue of the pattern of encoding features, an absolute position of the plunger rod relative to a fiducial position may be determined uniquely. Thus, the volume of fluid remaining in the reservoir, the rate of fluid delivery, and proper loading of the reservoir may be accurately ascertained. Additionally, the encoding may serve to uniquely identify a version of the reservoir which may be supplied in various versions corresponding, for example, to differing concentrations of a therapeutic agent to be dispensed.

An optical position encoder includes a scale having multiple tracks separated in a direction perpendicular to travel, the tracks including an incremental track and an absolute track, the scale interacting with an incident first light beam to generate a second light beam having components carrying respective optical patterns produced by the incremental track and absolute track respectively. The encoder further includes a set of optical detectors including at least first and second detector arrays of differing properties to detect the respective optical patterns produced by the incremental track and absolute track respectively, each of the first and second detector arrays spanning multiple tracks of the scale and configured to respond to a respective detector-specific component of the second light beam more strongly than to another component of the second beam specific to another of the detector arrays.

In implementations of a linear encoder force transducer, an encoder component generates light that enters a light input window of an encoder strip, and reflective surfaces disperse the light internally within the encoder strip. The encoder strip has etched lines formed cross-width of the encoder strip for emitted light that exits the encoder strip. The encoder component has gradated slots through which the emitted light from the encoder strip is detected by an array of photo transistors, each of the gradated slots corresponding to one of the photo transistors in the array of photo transistors. An encoder module can determine a linear displacement, such as representative of a force applied to a pen tip of a computer input pen, based on one or more of the photo transistors detecting the emitted light as the etched lines of the encoder strip move relative to the gradated slots of the encoder component.

An encoder includes a scale, a detector, and a processor. The processor executes a second process while executing a first process, calculates a first relative position of one of the scale and the detector to the other of the scale and the detector when a calculation of a relative position between them starts, and then calculates a second relative position of the one to the other based on a relative displacement amount between them and the first relative position.

An absolute encoder includes a light-emitting mechanism including a light-emitting surface and emitting detection light from the light-emitting surface. A light-receiving mechanism including a scale plate having a scale area and receiving at a light-receiving area the detection light emitted from the light-emitting surface and passing through the scale area of the scale plate. The light-emitting mechanism and the light-receiving mechanism are set to a positional relationship that inclines an irradiation axis extending from the light-emitting surface through the scale area to the light-receiving area relative to a rotation axis direction of the scale plate.

An optical position-measuring device for absolute position determination includes a material measure extending along a measurement direction and including an incremental graduation and an absolute code. A scanning unit movable relative to the material measure has a light source, a scanning grating for optically scanning the incremental graduation and a detector device. The detector device includes an incremental detector for generating incremental signals from the optical scanning of the incremental graduation and an absolute detector for generating absolute signals from optical scanning of the absolute code. A common detection plane is located at a defined perpendicular distance from the scanning grating and/or a periodicity of a fringe pattern on the incremental detector is selected such that, in the event of scattering contamination in a region of the material measure and/or the scanning grating, amplitudes of the incremental signals and the absolute signals drop off equally.

To obtain a position detection device capable of detecting highly accurate and robust position by suppressing affect of error detection of an edge, provided is a configuration for performing a validity determination of edges detected by binarizing an image signal (21) converted by a light-receiving element (3) for receiving light irradiated from a light source (1) toward a scale (2) having a code pattern, and performing position detection after removing the edges determined to be invalid as edges that have been affected by foreign matter and the like among the edges on which the validity determination has been performed.

A light source in a rotary optical encoder can illuminate a pattern on a rotatable shaft and an optical sensor can detect either the light that is reflected or transmitted based on the pattern. A sampling rate of the optical sensor is dynamically adjusted based on a rotational speed of the rotatable shaft. A pulse rate of the light source may also be dynamically adjusted based on the sampling rate of the optical sensor.

Phase estimation apparatus processes sensor signals from sensors to estimate a phase of a periodically varying state of an object, such as position of a moving object. A phase estimation processor applies a first correlation calculation to simultaneously collected samples of the sensor signals to generate first quadrature values, where the first correlation calculation employs variable calculation values, and applies a phase calculation to the first quadrature values to generate the phase estimation. A pre-quadrature calibration circuit applies respective second correlation calculations to respective sequences of samples of the sensor signals individually to generate second quadrature values for each of the sensor signals, and applies phase and/or magnitude calculations to the sets of second quadrature values to generate the variable calculation values for the first correlation calculation, thereby compensate for the error component and improve accuracy of the estimated phase.

There is provided a photoelectric encoder that can deconcentrate a calculation load in a photoelectric ABS encoder, and reduce power consumption.

A photoelectric encoder includes light receiving units 6 configured to output a plurality of photocurrent signals obtained by receiving light emitted from a light emission unit 5, via a scale SC, a signal conversion unit 10 configured to output a conversion signal by converting the plurality of photocurrent signals, a position calculation unit 20 configured to calculate an absolute position based on the conversion signal, and a microcomputer 3 configured to perform drive control of the light emission unit 5, the signal conversion unit 10, and the position calculation unit 20. The microcomputer 3 intermittently drives at least either one of the light emission unit 5 and the signal conversion unit 10, and causes the position calculation unit 20 to execute calculation according to a timing of intermit driving.