Abstract: An encoder configuration comprises an illumination portion, a scale comprising a scale track, and a signal processing electronics. The signal processing electronics may include a detector comprising a first set of three detector sub-portions that provide a first set of signals comprising three respective sub-portion signal subsets that have nominally the same signal characteristics when the scale track is not contaminated or defective. The processing electronics analyze the first set of signals and identify a least-similar sub-portion signal subset that has a corresponding signal characteristic value that is least similar to comparable signal characteristic values associated with more-similar sub-portion signal subsets of the first set of signals. Position measurements are based on valid signals including a plurality of the more-similar sub-portion signal subsets and not including the least-similar sub-portion signal subset if it is significantly different.

Abstract: An encoder configuration comprises a dual-modulation scale track pattern that provides a first intensity modulation component for producing periodic signals, and a second intensity modulation component for producing a long-range absolute signal. The dual-modulation scale track pattern increases the range-to-resolution ratio of the encoder without the use of additional scale tracks that would increase the width of the encoder components. The long-range signal may be encoded in the dual-modulation scale track pattern either by varying certain dimensions of pattern elements included in the scale track or by superimposing a layer including an optical density variation along on the track on pattern elements of similar areas. In either case, the net offset and/or amplitude levels of the associated signals are modified along the scale track. These modified offset and/or amplitude levels provide the basis for the long-range absolute signal.

Abstract: An encoder configuration comprises a dual-modulation scale track pattern that provides a first intensity modulation component for producing periodic signals, and a second intensity modulation component for producing a long-range absolute signal. The dual-modulation scale track pattern increases the range-to-resolution ratio of the encoder without the use of additional scale tracks that would increase the width of the encoder components. The long-range signal may be encoded in the dual-modulation scale track pattern either by varying certain dimensions of pattern elements included in the scale track or by superimposing a layer including an optical density variation along on the track on pattern elements of similar areas. In either case, the net offset and/or amplitude levels of the associated signals are modified along the scale track. These modified offset and/or amplitude levels provide the basis for the long-range absolute signal.

Abstract: An encoder configuration comprises an illumination portion, a scale comprising a scale track, and a signal processing electronics. The signal processing electronics may include a detector comprising a first set of three detector sub-portions that provide a first set of signals comprising three respective sub-portion signal subsets that have nominally the same signal characteristics when the scale track is not contaminated or defective. The processing electronics analyze the first set of signals and identify a least-similar sub-portion signal subset that has a corresponding signal characteristic value that is least similar to comparable signal characteristic values associated with more-similar sub-portion signal subsets of the first set of signals. Position measurements are based on valid signals including a plurality of the more-similar sub-portion signal subsets and not including the least-similar sub-portion signal subset if it is significantly different.

Abstract: A position sensor using a novel structured light generating scale or target member is provided. An imaging array is capable of measuring the relative translation and orientation of the structured light generating scale or target member in X, Y, Z, yaw, pitch, and roll (“6D”) simultaneously, and with high precision. The target member includes an array of lenses that provide an array of structured light patterns that diverge, converge, or both, to change the size of the corresponding structured light image as a function of the “Z” coordinate of the relative position, in various embodiments. The X-Y position of each individual structured light image on the imaging array varies with the relative X-Y position of the structured light generating target member, and the shape of structured light image changes as a function of the relative angular orientation.

Abstract: An induced current position transducer reduces spatial phase errors associated with layout constraints. Each winding of the transducer comprises a set of loops arranged in hypothetical basic polarity zones that alternate along the measuring axis and a set of loops arranged in hypothetical offset polarity zones that are offset from the basic polarity zones along the measuring axis. Hypothetical offset zones are defined at positions where basic and offset polarity zones that have opposite polarities overlap. Due to layout constraints, each winding may have an offset zone including an unbalancing coupling area that differs from the coupling area in the majority of offset zones. The windings are configured such that the amount of unbalanced coupling area included in the offset zones of each respective winding is approximately the same for each of the windings, making their respective phase errors approximately the same.

Abstract: A position sensor using a novel optical path array (OPA) element, an angle-selective spatial filter, and an imaging array is capable of measuring the translation and orientation relative to a target member in X, Y, Z, yaw, pitch, and roll (“6D”) simultaneously, and with high precision. A target member includes an array of target points surrounded by a contrasting surface. The position sensor uses the OPA element in combination with the angle-selective spatial filter in a target point imaging arrangement such that the imaging array of the position sensor only receives light rays that enter the OPA element according to an operable cone angle ?. Accordingly, each target point generally produces a ring-shaped image having a size on the imaging array that varies with the Z position of each target point. The X-Y position of each target point image on the imaging array varies with the X-Y position of each target point.