Abstract: An opto-magnetic rotary position encoder includes a polarization optical encoder and a magnetic encoder, both configured for on-axis placement and operation with respect to a rotational axis of a rotating component. A polarization sensor digital control block and a magnetic sensor digital control block are configured and operative to combine polarizer channel position data and magnetic channel position data in a manner providing for one or more of (1) redundancy, (2) calibration, (3) monitoring performance of one channel in relation to the other channel, or (4) compensation or correction of one channel based on the other channel.

Abstract: A rotary optical position encoder includes a source of a linear-polarized light beam, a polarization-sensitive detector, and a rotating retarder disposed for rotation between the source and the detector. The retarder is configured and operative to produce a polarized exit beam whose polarization state rotates at a rate greater than a rotation rate of the retarder, thereby for increased resolution over a similar encoder using a rotating polarizer element. In an example, when polarized light is incident upon a rotating half-wave retarder, the transmitted beam's polarization axis rotates at twice the rate of retarder rotation, resulting in an electrical detector output that varies four times per revolution. Resolution is improved accordingly, as a given detected increment at the output is produced by only one-half the physical rotation increment required for a simple polarizer.

Abstract: A Halbach-based magnetic position sensor includes a Halbach magnetic element having a spatially rotating magnetization pattern along an extent, producing a focused and augmented magnetic field on a working side relative to a magnetic field on a non-working side. A sensing element on the working side is co-configured with the Halbach magnetic element for relative motion therebetween. The sensing element includes encoder circuitry and magnetic sensors that sense the working-side magnetic field and produce corresponding sensor signals. The encoder circuitry translates the sensor signals into position signals indicating relative position between the sensing element and the Halbach magnetic element. In one example the Halbach magnetic element has a closed curve (e.g., substantially circular or ring-like) configuration.

Abstract: A rotary position encoder includes a detection unit and a scale co-configured and co-operative to detect a relative rotational position and to generate a position output accordingly. The scale has a scale pattern according to a linear-feedback shift register (LFSR) pseudo-random code, which is a non-maximal length code having a seed value, tap positions, and modified least-significant bit position(s) of code words that satisfy rotary constraint by which each code word follows in sequence from the adjacent code word.

Abstract: An external optical feedback element (108) for tuning an output beam of a gas laser (102) having multiple wavelengths includes a partially reflective optical element (108) positioned on a beam path of the output beam (106) outside of an internal optical cavity of the gas laser (102), and a stage (114) to support the optical element and adjust rotation, horizontal tilt angle, and vertical tilt angle of the optical element with respect to the beam path. The output beam (106) is partially reflected at the optical element (108) and fed back into the internal optical cavity of the gas laser (102), with the intensity varying for multiple wavelengths and adjusted by changing rotation, horizontal tilt angle and vertical tilt angle of the optical element. Thereby, a variable feedback of the output beam into the internal optical cavity of the gas laser is provided, which leads to a selective output wavelength of the gas laser, either at a single line or at multiple lines simultaneously.

Abstract: A machine vision system that uses an imager to capture an optical image of a target object that may contain a liquid. The target object is illuminated by an illumination source positioned oppositely from the imager and a predetermined pattern is positioned between the illumination source and the target object so that the imager will capture optical images of the background pattern through any liquid positioned in the target object. A processor is programmed to analyze captured images to detect any distortions of the pattern that are attributable to the presence of a liquid in the target object.

Abstract: An absolute position encoder includes a position location medium containing position identifier code words providing absolute position indications, and an optical source, an optical detector, an optics subsystem and a code word decoder. The optics subsystem focuses a source beam onto the position location medium and directs a return beam to the optical detector, detects a focus condition from the return beam, and automatically adjusts focus of the source beam to maintain a predetermined focus condition during operation. The code word decoder responds to the detector signal to detect a code word and generate a decoder output indicative of a corresponding code word value and corresponding detected position.

Abstract: A machine vision system that uses an imager to capture an optical image of a target object that may contain a liquid. The target object is illuminated by an illumination source positioned oppositely from the imager and a predetermined pattern is positioned between the illumination source and the target object so that the imager will capture optical images of the background pattern through any liquid positioned in the target object. A processor is programmed to analyze captured images to detect any distortions of the pattern that are attributable to the presence of a liquid in the target object.

Abstract: A method is disclosed of fabricating a mirror for use in limited rotation motor systems, said method comprising the steps of providing a mirror structure including at least one wall section, and exposing the at least one wall section to a fluid etching agent to thereby provide chemical milling of the mirror structure.

Abstract: An external optical feedback element (108) for tuning an output beam of a gas laser (102) having multiple wavelengths includes a partially reflective optical element (108) positioned on a beam path of the output beam (106) outside of an internal optical cavity of the gas laser (102), and a stage (114) to support the optical element and adjust rotation, horizontal tilt angle, and vertical tilt angle of the optical element with respect to the beam path. The output beam (106) is partially reflected at the optical element (108) and fed back into the internal optical cavity of the gas laser (102), with the intensity varying for multiple wavelengths and adjusted by changing rotation, horizontal tilt angle and vertical tilt angle of the optical element. Thereby, a variable feedback of the output beam into the internal optical cavity of the gas laser is provided, which leads to a selective output wavelength of the gas laser, either at a single line or at multiple lines simultaneously.

Abstract: A communication system that involves superimposing data over DC power. The data takes the form of high bitrate digital signals, where the bitrate is much higher than 0 Hz (DC); this separation allows the AC signal to be easily separated from the DC power. The physical system consists of a two conductor cable, and integration is modular, in that multiple slaves can be connected and disconnected to a master through a routing bus also comprising two conductors. The master can communicate bi-directionally with the slave(s), and the data is encoded using DC-balanced encoding in an FPGA. The data is sent to and from a differential signaling transmitter/receiver pairs at each end of the cable. The system is may be used with position sensors, and provides the benefit of reducing cable costs and sensor size due to the decrease in number of conductors and elimination of power components in the sensor.

Abstract: 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.

Abstract: A communication system that involves superimposing data over DC power. The data takes the form of high bitrate digital signals, where the bitrate is much higher than 0 Hz (DC); this separation allows the AC signal to be easily separated from the DC power. The physical system consists of a two conductor cable, and integration is modular, in that multiple slaves can be connected and disconnected to a master through a routing bus also comprising two conductors. The master can communicate bi-directionally with the slave(s), and the data is encoded using DC-balanced encoding in an FPGA. The data is sent to and from a differential signaling transmitter/receiver pairs at each end of the cable. The system is may be used with position sensors, and provides the benefit of reducing cable costs and sensor size due to the decrease in number of conductors and elimination of power components in the sensor.

Abstract: A system for controlling whether a battery powered device tethered to a host via a Universal Serial Bus (USB) interface will charge its battery via the USB connection. A USB interface adapter is programmed to control charging of the device battery based on whether a standard data terminal ready (DTR) signal is received from the host through a USB to RS-232 converter. Data packets are sent via the USB data line and interpreted as a DTR signal by the USB to Serial adapter. The dedicated DTR output pin from the adapter is thus used to control the charging circuit.

Abstract: 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.