Abstract: A chromatically dispersive lens configuration including thermal compensation may be utilized in chromatic confocal point sensor optical pens for chromatic range sensing. The lens configuration may include a negative power doublet lens and a positive power lens portion. The positive power lens portion comprises at least two lens elements which compensate for the overall thermal sensitivity of a chromatic confocal point sensor optical pen. The lens elements of the positive power lens portion which compensate for thermal sensitivity have an average coefficient of thermal defocus which is in a range that is at lowest 10 ppm per 10° C. The lens configuration can be implemented with dimensions which fit a standard commercial chromatic confocal point sensor optical pen, while maintaining a level of optical performance sufficient for chromatic range sensing.

Abstract: A chromatically dispersive lens configuration including thermal compensation may be utilized in chromatic confocal point sensor optical pens for chromatic range sensing. The lens configuration may include a negative power doublet lens and a positive power lens portion. The positive power lens portion comprises at least two lens elements which compensate for the overall thermal sensitivity of a chromatic confocal point sensor optical pen. The lens elements of the positive power lens portion which compensate for thermal sensitivity have an average coefficient of thermal defocus which is in a range that is at lowest 10 ppm per 10° C. The lens configuration can be implemented with dimensions which fit a standard commercial chromatic confocal point sensor optical pen, while maintaining a level of optical performance sufficient for chromatic range sensing.

Abstract: A method of determining an amount of tilt may include projecting at least two coherent wavefronts toward a target surface, the wavefronts reflecting from the target surface to create an interference fringe pattern on a detector, and transmitting a beam toward the target surface, the transmitted beam reflecting from the target surface to form a beam spot on the detector. A fringe pitch indicative of a distance to the target surface may be determined based on the interference fringe pattern. A displacement on the detector of the beam spot, relative to a nominal location of the beam spot when the target surface is at a nominal angle of incidence relative to the beam, may be determined. The amount of tilt of the target surface relative to the nominal angle of incidence, may be determined based on the displacement of the beam spot and the determined fringe pitch.

Abstract: A system and method for improving the accuracy of a speckle-based image correlation displacement sensor provides ultra-high accuracy by ensuring that, in the absence of motion, the speckle image does not vary over time. In one embodiment, the speckle image is stabilized by reducing or compensating for laser diode wavelength changes. Various methods for stabilizing the wavelength include thermoelectric temperature control, measuring and correcting the wavelength by any suitable means, or providing a specific wavelength of light feedback from an external grating. Image stabilization may also be accomplished by monitoring the warm-up process of the system. Once the system is determined to have completed the warm-up process, an indicator is provided to the user to indicate that the system is ready for use. Sensor geometric configurations that reduce or eliminate wavelength-related errors are also disclosed.

Abstract: A position error correcting, or reducing, method and system used in an image-correlation system which obtains an error function generally reflecting an error occurring over a nominal reference image update length and an error occurring at a first frequency and various other system errors. The error can be compared to a first reference to fit the position error. In various embodiments, parameters of an error function can be varied in fitting the error function to the first reference. The obtained error function can then be used to determine the position error and render more accurate the image correlation system. In one exemplary implementation, the first frequency is related to a pixel pitch and the nominal reference image update length related to the distance between reference image changes is the maximum usable reference image update length.

Abstract: An absolute 2D position-sensing device is usable to measure the position of a first element with respect to a second element. A 2D absolute scale includes an integrated 2D absolute scale pattern extending over the 2D scale area along each measuring axis of the scale. The integrated 2D absolute scale pattern includes a predetermined quasi-random pattern repeatedly interleaved with a plurality of code portions along each axis. Each code portion includes a plurality of code elements indicative of an absolute measurement value. The offset of the quasi-random pattern relative to a readhead of the device is combined with the absolute measurement value to determine an absolute position to a very high resolution over a relatively large 2D range.

Abstract: An absolute 2D position-sensing device is usable to measure the position of a first element with respect to a second element. A 2D absolute scale includes an integrated 2D absolute scale pattern extending over the 2D scale area along each measuring axis of the scale. The integrated 2D absolute scale pattern includes a predetermined quasi-random pattern repeatedly interleaved with a plurality of code portions along each axis. Each code portion includes a plurality of code elements indicative of an absolute measurement value. The offset of the quasi-random pattern relative to a readhead of the device is combined with the absolute measurement value to determine an absolute position to a very high resolution over a relatively large 2D range.

Abstract: An absolute 2D position-sensing device is usable to measure the relative position of two elements. A 2D absolute scale includes an integrated 2D absolute scale pattern extending over the 2D scale area along each measuring axis of the scale. The integrated 2D absolute scale pattern includes a plurality of periodic portions interleaved with a plurality of non-periodic portions along each axis. Each periodic portion includes a plurality of periodically-placed scale elements. Each non-periodic portion includes a plurality of code elements indicative of an absolute measurement value. The code elements may have a length that is narrower along each measuring axis is than the length of the periodic scale elements along each measuring axis. The offset of the periodically-placed elements relative to a readhead of the device is combined with the absolute measurement value to determine an absolute position.

Abstract: An optical displacement sensing device is provided for determining the relative displacement of a diffraction scale grating that may have a grating pitch less than the wavelength of the light of the sensing device. The sensing device includes a split light beam input portion for inputting two split light beams along respective light paths, and light beam directing elements for directing the two split beams along converging light paths toward a first zone on the scale grating to give rise to two diffracted beams along light paths which diverge. The sensing device further includes retroreflector elements for receiving the two diverging diffracted beams and retroreflecting them along light paths which converge toward a second zone on the scale grating to give rise to two later-diffracted light beams that are then directed to a shared zone. The retroreflectors may be positioned to eliminate cross-over beams and the need for polarizers.

Abstract: An absolute 2D position-sensing device is usable to measure the relative position of two elements. A 2D absolute scale includes an integrated 2D absolute scale pattern extending over the 2D scale area along each measuring axis of the scale. The integrated 2D absolute scale pattern includes a plurality of periodic portions interleaved with a plurality of non-periodic portions along each axis. Each periodic portion includes a plurality of periodically-placed scale elements. Each non-periodic portion includes a plurality of code elements indicative of an absolute measurement value. The code elements may have a length that is narrower along each measuring axis is than the length of the periodic scale elements along each measuring axis. The offset of the periodically-placed elements relative to a readhead of the device is combined with the absolute measurement value to determine an absolute position.

Abstract: An absolute position-sensing device is usable to measure the relative position of two elements. An absolute scale includes an integrated track extending along a measuring axis of the scale. The integrated track includes a plurality of periodic portions interleaved with a plurality of non-periodic portions. Each periodic portion includes a plurality of periodically-placed scale elements. Each non-periodic portion includes a plurality of code elements indicative of an absolute measurement value. The code elements may have a length that is narrower along the measuring axis than the length of the periodic scale elements. The offset of the periodic-placed elements relative to a readhead of the device is combined with the absolute measurement value to determine an absolute position.

Abstract: An optical displacement sensing device is provided for determining the relative displacement of a diffraction grating scale along a measuring axis. The grating may be reflective and the grating pitch may be less than the wavelength of the light of the displacement sensing device. The sensing device includes a split light beam input portion for inputting two split light beams along respective light paths, and light beam directing elements for directing the two split beams to converge proximate to a first zone on the scale grating to give rise to two diffracted beams which diverge proximate to the first zone. The sensing device further includes retroreflector elements for receiving and retroreflecting the two diffracted beams to converge proximate to a second zone on the scale grating to give rise to two later-diffracted light beams which diverge and are directed to a shared zone.

Abstract: An optical displacement sensing device is provided for determining the relative displacement of a diffraction scale grating that may have a grating pitch less than the wavelength of the light of the sensing device. The sensing device includes a split light beam input portion for inputting two split light beams along respective light paths, and light beam directing elements for directing the two split beams along converging light paths toward a first zone on the scale grating to give rise to two diffracted beams along light paths which diverge. The sensing device further includes retroreflector elements for receiving the two diverging diffracted beams and retroreflecting them along light paths which converge toward a second zone on the scale grating to give rise to two later-diffracted light beams that are then directed to a shared zone. The retroreflectors may be positioned to eliminate cross-over beams and the need for polarizers.

Abstract: A position error correcting, or reducing, method and system used in an image-correlation system which obtains an error function generally reflecting an error occurring over a nominal reference image update length and an error occurring at a first frequency and various other system errors. The error can be compared to a first reference to fit the position error. In various embodiments, parameters of an error function can be varied in fitting the error function to the first reference. The obtained error function can then be used to determine the position error and render more accurate the image correlation system. In one exemplary implementation, the first frequency is related to a pixel pitch and the nominal reference image update length related to the distance between reference image changes is the maximum usable reference image update length.

Abstract: A laser system and method for beam enhancement utilizes shaped electrodes or one or more shaped lasing media, including crystal media, to prescribe the operational transverse modes of a laser beam produced by the laser. The electrodes and shaped lasing media are shaped with respect to the transverse mode or modes to be selected for operational use. In some embodiments shaping is done according to a desired mode so that the desired mode has the highest power level of any of the modes present in the laser beam during operation of the laser. In some embodiments, the electrodes or lasing media are so shaped that the total power of the laser beam fluctuates below plus and minus 10% of an average total power level. Some embodiments utilize folded resonators. Other embodiments utilize other resonators including resonators having multiple discharge sections and are not folded.

Abstract: A laser system and method for beam enhancement utilizes shaped electrodes or one or more shaped lasing media, including crystal media, to prescribe the operational transverse modes of the laser. The electrodes and shaped lasing media are shaped with respect to the transverse mode or modes to be selected for operational use. In some embodiments shaping is done according to the selected transverse modes for operation so that at least a designated percentage of the total operational power of the beam is made up of the selected transverse modes. The designated percentage of total operational power of the selected transverse modes can be 90% of the total power of the beam, but in other more relaxed cases can be 85% and in other more stringent cases are 95% of the beam. In some embodiments, the electrodes or lasing media are so shaped that the theoretical fundamental transverse mode is the only selected transverse operational mode. Some embodiments utilize folded resonators.

Abstract: A laser with a heat transfer system and method of making the same using electrodes. The heat transfer system draws heat from the electrodes which have internal electrode surfaces adjacent to a lasing medium of the laser. Cooling of the electrodes helps to maintain proper operating temperature for the lasing medium. The heat transfer system utilizes thermally conductive material positioned between external surfaces of the electrodes and internal surfaces of a housing that contains the electrodes and the lasing medium. Since the thermally conductive material adds capacitance to the laser system, inductance may be added for compensation depending upon the amount of thermally conductive material used.

Abstract: A laser assembly system and method uses an electrode assembly and flexible housing to reduce manufacturing costs and complexity. The flexible housing also helps to insure uniform contact with the housing and electrically insulating material between the housing and electrodes. The uniform contact in turn assists in maintaining a uniform electric field in the discharge area of the laser, which affects laser performance, and assists in maintaining efficient cooling of the electrodes and the lasing medium. The electrode assembly is pre-assembled before insertion into the laser housing, which reduces adverse effects of anomalies of housing construction and helps to reduce the complexity and cost of manufacturing of the laser. The electrode assembly includes first and second electrodes that are separated by spacers made out of an electrically insulating material such as ceramic.

Abstract: The present invention provides shift mechanisms and methods of controlling a transmission. According to one embodiment of the present invention, a shift mechanism for use with a transmission includes a central axle defining a central axis; a master cylinder configured to increase the pressure of a liquid; and an eccentric assembly comprising a support member provided about the central axle and an eccentric mount coupled with the support member, the eccentric mount defining an eccentric axis and being in fluid communication with the master cylinder and configured to provide radial adjustment of the eccentric axis relative to the central axis providing adjustment of the gear ratio of the transmission.