Abstract: Interferometric systems and methods for measuring rotational movement are described. In one implementation, an interferometer for measuring rotational movement includes a housing and a light source within the housing configured to project coherent light toward a non-coded surface of an object. The interferometer further includes at least one optical element configured to modify the projected coherent light in a manner accounting for a rotation of the object. The interferometer also includes at least one sensor within the housing including at least one light detector configured to detect reflections of the modified projected coherent light from the opposing non-coded surface as the object rotates relative to the housing. The interferometer further includes at least one processor configured to receive input from the at least one sensor and determine an amount of rotation of the object around the at least one rotational axis.

Abstract: Devices and methods are disclosed for determining relative motion. In one implementation, an interferometer is provided. The interferometer may include a body, a light source configured to project a coherent light to an opposing surface, a plurality of pairs of light detectors configured to convert reflections of the coherent light into photocurrents, and a processor. The processor may be configured to detect changes in the photocurrents, wherein a first change in the photocurrents, which occurs in response to a relative motion between the body and the opposing surface, represents a motion signal, and a second change in the photocurrents represents a noise signal. The processor may also determine the relative motion between the body and the opposing surface based on the first change in the photocurrents when a ratio between a power of the motion signal and a power of the noise signal is below about 10.

Abstract: Devices and methods are disclosed generating input. In one implementation, a stylus is provided for generating writing input. The stylus includes an elongated body having a distal end, and a light source configured to project coherent light on an opposing surface adjacent the distal end. The stylus further includes at least one sensor configured to measure first reflections of the coherent light from the opposing surface while the distal end moves in contact with the opposing surface, and to measure second reflections of the coherent light from the opposing surface while the distal end moves above the opposing surface and out of contact with the opposing surface. The stylus also includes at least one processor configured to receive input from the at least one sensor and to enable determining three dimensional positions of the distal end based on the first reflections and the second reflections.

Abstract: Devices and methods are disclosed for determining relative motion. In one implementation, an interferometer is provided. The interferometer may include a body, a light source configured to project a coherent light to an opposing surface, a plurality of pairs of light detectors configured to convert reflections of the coherent light into photocurrents, and a processor. The processor may be configured to detect changes in the photocurrents, wherein a first change in the photocurrents, which occurs in response to a relative motion between the body and the opposing surface, represents a motion signal, and a second change in the photocurrents represents a noise signal. The processor may also determine the relative motion between the body and the opposing surface based on the first change in the photocurrents when a ratio between a power of the motion signal and a power of the noise signal is below about 10.

Abstract: Devices and methods are disclosed for determining relative motion. In one implementation, an interferometer is provided. The interferometer may include a body, a light source configured to project a coherent light to an opposing surface, a plurality of pairs of light detectors configured to convert reflections of the coherent light into photocurrents, and a processor. The processor may be configured to detect changes in the photocurrents, wherein a first change in the photocurrents, which occurs in response to a relative motion between the body and the opposing surface, represents a motion signal, and a second change in the photocurrents represents a noise signal. The processor may also determine the relative motion between the body and the opposing surface based on the first change in the photocurrents when a ratio between a power of the motion signal and a power of the noise signal is below about 10.

Abstract: Interferometric systems and methods for measuring rotational movement are described. In one implementation, an interferometer for measuring rotational movement includes a housing and a light source within the housing configured to project coherent light toward a non-coded surface of an object. The interferometer further includes at least one optical element configured to modify the projected coherent light in a manner accounting for a rotation of the object. The interferometer also includes at least one sensor within the housing including at least one light detector configured to detect reflections of the modified projected coherent light from the opposing non-coded surface as the object rotates relative to the housing. The interferometer further includes at least one processor configured to receive input from the at least one sensor and determine an amount of rotation of the object around the at least one rotational axis.

Abstract: Devices and methods are disclosed generating input. In one implementation, a stylus is provided for generating writing input. The stylus includes an elongated body having a distal end, and a light source configured to project coherent light on an opposing surface adjacent the distal end. The stylus further includes at least one sensor configured to measure first reflections of the coherent light from the opposing surface while the distal end moves in contact with the opposing surface, and to measure second reflections of the coherent light from the opposing surface while the distal end moves above the opposing surface and out of contact with the opposing surface. The stylus also includes at least one processor configured to receive input from the at least one sensor and to enable determining three dimensional positions of the distal end based on the first reflections and the second reflections.

Abstract: Devices and methods are disclosed for generating input. In one implementation, a stylus is provided for generating writing input. The stylus includes an elongated body having a distal end, and a light source configured to project coherent light on an opposing surface adjacent the distal end. The stylus further includes at least one sensor configured to measure first reflections of the coherent light from the opposing surface while the distal end moves in contact with the opposing surface, and to measure second reflections of the coherent light from the opposing surface while the distal end moves above the opposing surface and out of contact with the opposing surface. The stylus also includes at least one processor configured to receive input from the at least one sensor and to enable determining three dimensional positions of the distal end based on the first reflections and the second reflections.

Abstract: Devices and methods are disclosed for determining relative motion. In one implementation, an interferometer is provided. The interferometer may include a body, a light source configured to project a coherent light to an opposing surface, a plurality of pairs of light detectors configured to convert reflections of the coherent light into photocurrents, and a processor. The processor may be configured to detect changes in the photocurrents, wherein a first change in the photocurrents, which occurs in response to a relative motion between the body and the opposing surface, represents a motion signal, and a second change in the photocurrents represents a noise signal. The processor may also determine the relative motion between the body and the opposing surface based on the first change in the photocurrents when a ratio between a power of the motion signal and a power of the noise signal is below about 10.

Abstract: Devices and methods are disclosed for generating input. In one implementation, a stylus is provided for generating writing input. The stylus includes an elongated body having a distal end, and a light source configured to project coherent light on an opposing surface adjacent the distal end. The stylus further includes at least one sensor configured to measure first reflections of the coherent light from the opposing surface while the distal end moves in contact with the opposing surface, and to measure second reflections of the coherent light from the opposing surface while the distal end moves above the opposing surface and out of contact with the opposing surface. The stylus also includes at least one processor configured to receive input from the at least one sensor and to enable determining three dimensional positions of the distal end based on the first reflections and the second reflections.

Abstract: A method for determining the relative motion of a surface with respect to a measurement device including placing a partially transmitting object, which is part of the measuring device, adjacent to the surface; illuminating the surface with incident illumination, which does not constitute an interference pattern, such that the illumination is reflected from portions of the surface, wherein at least part of at least one of the incident and reflected illumination passes through the object; detecting the illumination reflected from the surface, and generating a detected signal; and determining the relative motion of the surface parallel to the surface, from the detected signal.

Abstract: A method of detecting the passage of an edge of a moving sheet of material at a position comprising: monitoring a state of motion at a position; and determining a time of an edge of the sheet at a position as a time at which a change in a state of motion at the position is detected.

Abstract: A method for determining the relative motion of a surface with respect to a measurement device, comprising: illuminating the surface with incident illumination, having a coherence length, such that the illumination is reflected from portions of the surface, wherein at least part of at least one of the incident and reflected illumination passes through a partially transmitting object that is part of the measuring device; detecting the illumination reflected from the surface, to generate a detected signal; and determining the relative motion of the surface parallel to the surface, from the detected signal, wherein the object and the surface are situated within a distance that is less than the coherence length of the detected illumination.

Abstract: A method for determining the relative motion of a surface with respect to a measurement device comprising: illuminating the surface with incident illumination; detecting illumination reflected from the surface to form at least one detected signal; and determining the amount of relative motion parallel to the surface from said at least one detected signal, characterized in that said determining includes correcting for the effects of relative motion perpendicular to the surface.

Abstract: A method for determining the relative motion of a surface with respect to a measurement device comprising: illuminating the surface from a source with incident illumination, such that illumination is reflected from portions of the surface toward a detector; spatially filtering the reflected illumination such that the phase of the detected optical illumination from a given scatterer on the surface is substantially constant or linearly related to the translation of the surface; generating a signal by the detector responsive to the illumination incident on the detector; and determining the relative motion of the surface from the signal.