Winding and scale configuration for inductive position encoder
First Claim
1. An electronic position encoder usable to measure a relative position between two elements along a measuring axis direction that coincides with an x-axis direction, the electronic position encoder comprising:
- a scale extending along the measuring axis direction and including a signal modulating scale pattern comprising first and second pattern tracks arranged parallel to one another, each pattern track having a track width dimension along a y-axis direction that is perpendicular to the x-axis direction between its interior boundary that is closest to the other pattern track and its exterior boundary that is farthest from the other pattern track, and each pattern track comprising signal modulating elements that are arranged to provide a spatially varying characteristic which changes as a periodic function of position along the x-axis direction;
a detector portion configured to be mounted proximate to the pattern tracks and to move along the measuring axis direction relative to the pattern tracks, the detector portion comprising;
a field generating coil configuration fixed on a substrate, comprising;
a first-track field generating coil portion comprising first-track inside and outside elongated portions, the first-track field generating coil portion surrounding a first interior area aligned with the first pattern track and having a nominal first interior area length dimension along the x-axis direction and a nominal first interior area width dimension along the y-axis direction, the nominal first interior area width dimension extending from the first-track inside elongated portion to the first-track outside elongated portion, the first-track field generating coil portion generating a changing first magnetic flux in the first interior area in response to a coil drive signal, anda second-track field generating coil portion comprising second-track inside and outside elongated portions, the second-track field generating coil portion surrounding a second interior area aligned with the second pattern track and having a nominal second interior area length dimension along the x-axis direction and a nominal second interior area width dimension along the y-axis direction, the nominal second interior area width dimension extending from the second-track inside elongated portion to the second-track outside elongated portion, the second-track field generating coil portion generating a changing magnetic flux in the second interior area in response to the coil drive signal; and
a plurality of sensing elements arranged along the x-axis direction and fixed on the substrate, each of the sensing elements having a nominal sensing element width dimension along the y-axis direction that spans the first and second interior areas, wherein the plurality of sensing elements are configured to provide detector signals which respond to a local effect on the changing magnetic flux provided by adjacent signal modulating elements of the scale pattern; and
a signal processing configuration that is operably connected to the detector portion to provide the coil drive signal and that determines the relative position between the detector portion and the scale pattern based on detector signals input from the detector portion,wherein;
the field generating coil configuration comprises;
an input portion comprising at least two connection portions that connect the coil drive signal from the signal processing configuration to the field generating coil configuration;
the first-track inside and outside elongated portions extending along the x-axis direction adjacent to the first interior area, the first-track inside elongated portion located adjacent to the first-track interior boundary and the first-track outside elongated portion located adjacent to the first-track exterior boundary, the first-track inside and outside elongated portions each comprising a conductive trace having a nominal first-track generating trace width dimension along the y-axis direction; and
the second-track inside and outside elongated portions extending along the x-axis direction adjacent to the second interior area, the second-track inside elongated portion located adjacent to the second-track interior boundary and the second-track outside elongated portion located adjacent to the second-track exterior boundary, the second-track inside and outside elongated portions each comprising a conductive trace having a nominal second-track generating trace width dimension along the y-axis direction;
at least a majority of the nominal sensing element width dimension is included between the first-track outside elongated portion and the second-track outside elongated portion, andthe field generating coil configuration is configured such that each nominal first-track generating trace width dimension is at least 0.1 times the nominal first interior area width dimension, and each nominal second-track generating trace width dimension is at least 0.1 times the nominal second interior area width dimension.
1 Assignment
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Accused Products
Abstract
An electronic position encoder includes a scale comprising first and second pattern tracks including respective signal modulating scale patterns, a detector and a signal processing configuration. The detector includes first-track and second-track field generating coil portions that surround first and second interior areas aligned with the first pattern track and second pattern track, respectively. The first-track and second-track field generating coil portions each include first and second elongated portions extending along the measuring axis direction, connected to end portions extending along a y-axis direction transverse to the measuring axis. The detector includes sensing elements that span across the first and second interior areas along the y-axis direction. A nominal y-axis trace width dimension of the elongated portions is at least 0.1 times a y-axis width of the first and/or second interior areas. In various implementations, a shielded end section may be used to connect the elongated portions.
70 Citations
21 Claims
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1. An electronic position encoder usable to measure a relative position between two elements along a measuring axis direction that coincides with an x-axis direction, the electronic position encoder comprising:
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a scale extending along the measuring axis direction and including a signal modulating scale pattern comprising first and second pattern tracks arranged parallel to one another, each pattern track having a track width dimension along a y-axis direction that is perpendicular to the x-axis direction between its interior boundary that is closest to the other pattern track and its exterior boundary that is farthest from the other pattern track, and each pattern track comprising signal modulating elements that are arranged to provide a spatially varying characteristic which changes as a periodic function of position along the x-axis direction; a detector portion configured to be mounted proximate to the pattern tracks and to move along the measuring axis direction relative to the pattern tracks, the detector portion comprising; a field generating coil configuration fixed on a substrate, comprising; a first-track field generating coil portion comprising first-track inside and outside elongated portions, the first-track field generating coil portion surrounding a first interior area aligned with the first pattern track and having a nominal first interior area length dimension along the x-axis direction and a nominal first interior area width dimension along the y-axis direction, the nominal first interior area width dimension extending from the first-track inside elongated portion to the first-track outside elongated portion, the first-track field generating coil portion generating a changing first magnetic flux in the first interior area in response to a coil drive signal, and a second-track field generating coil portion comprising second-track inside and outside elongated portions, the second-track field generating coil portion surrounding a second interior area aligned with the second pattern track and having a nominal second interior area length dimension along the x-axis direction and a nominal second interior area width dimension along the y-axis direction, the nominal second interior area width dimension extending from the second-track inside elongated portion to the second-track outside elongated portion, the second-track field generating coil portion generating a changing magnetic flux in the second interior area in response to the coil drive signal; and a plurality of sensing elements arranged along the x-axis direction and fixed on the substrate, each of the sensing elements having a nominal sensing element width dimension along the y-axis direction that spans the first and second interior areas, wherein the plurality of sensing elements are configured to provide detector signals which respond to a local effect on the changing magnetic flux provided by adjacent signal modulating elements of the scale pattern; and a signal processing configuration that is operably connected to the detector portion to provide the coil drive signal and that determines the relative position between the detector portion and the scale pattern based on detector signals input from the detector portion, wherein; the field generating coil configuration comprises; an input portion comprising at least two connection portions that connect the coil drive signal from the signal processing configuration to the field generating coil configuration; the first-track inside and outside elongated portions extending along the x-axis direction adjacent to the first interior area, the first-track inside elongated portion located adjacent to the first-track interior boundary and the first-track outside elongated portion located adjacent to the first-track exterior boundary, the first-track inside and outside elongated portions each comprising a conductive trace having a nominal first-track generating trace width dimension along the y-axis direction; and the second-track inside and outside elongated portions extending along the x-axis direction adjacent to the second interior area, the second-track inside elongated portion located adjacent to the second-track interior boundary and the second-track outside elongated portion located adjacent to the second-track exterior boundary, the second-track inside and outside elongated portions each comprising a conductive trace having a nominal second-track generating trace width dimension along the y-axis direction; at least a majority of the nominal sensing element width dimension is included between the first-track outside elongated portion and the second-track outside elongated portion, and the field generating coil configuration is configured such that each nominal first-track generating trace width dimension is at least 0.1 times the nominal first interior area width dimension, and each nominal second-track generating trace width dimension is at least 0.1 times the nominal second interior area width dimension. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. An electronic position encoder usable to measure a relative position between two elements along a measuring axis direction that coincides with an x-axis direction, the electronic position encoder comprising:
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a scale extending along the measuring axis direction and including a signal modulating scale pattern comprising first and second pattern tracks arranged parallel to one another, each pattern track having a track width dimension along a y-axis direction that is perpendicular to the x-axis direction between its interior boundary that is closest to the other pattern track and its exterior boundary that is farthest from the other pattern track, and each pattern track comprising signal modulating elements that are arranged to provide a spatially varying characteristic which changes as a periodic function of position along the x-axis direction; a detector portion configured to be mounted proximate to the pattern tracks and to move along the measuring axis direction relative to the pattern tracks, the detector portion comprising; a field generating coil configuration fixed on a substrate, comprising; a first-track field generating coil portion surrounding a first interior area aligned with the first pattern track and having a nominal first interior area length dimension along the x-axis direction and a nominal first interior area width dimension along the y-axis direction and generating a changing first magnetic flux in the first interior area in response to a coil drive signal, and a second-track field generating coil portion surrounding a second interior area aligned with the second pattern track and having a nominal second interior area length dimension along the x-axis direction and a nominal second interior area width dimension along the y-axis direction and generating a changing magnetic flux in the second interior area in response to the coil drive signal; and a plurality of sensing elements arranged along the x-axis direction and fixed on the substrate, each of the sensing elements having a nominal sensing element width dimension along the y-axis direction that spans the first and second interior areas, wherein the plurality of sensing elements are configured to provide detector signals which respond to a local effect on the changing magnetic flux provided by adjacent signal modulating elements of the scale pattern; and a signal processing configuration that is operably connected to the detector portion to provide the coil drive signal and that determines the relative position between the detector portion and the scale pattern based on detector signals input from the detector portion, wherein; the field generating coil configuration comprises; an input portion comprising at least two connection portions that connect the coil drive signal from the signal processing configuration to the field generating coil configuration; first-track inside and outside elongated portions extending along the x-axis direction adjacent to the first interior area, the first-track inside elongated portion located adjacent to the first-track interior boundary and the first-track outside elongated portion located adjacent to the first-track exterior boundary, the first-track inside and outside elongated portions each having a nominal first-track generating trace width dimension along the y-axis direction; and second-track inside and outside elongated portions extending along the x-axis direction adjacent to the second interior area, the second-track inside elongated portion located adjacent to the second-track interior boundary and the second-track outside elongated portion located adjacent to the second-track exterior boundary, the second-track inside and outside elongated portions each having a nominal second-track generating trace width dimension along the y-axis direction; at least a majority of the nominal sensing element width dimension is included between the first-track outside elongated portion and the second-track outside elongated portion; the field generating coil configuration is configured such that each nominal first-track generating trace width dimension is at least 0.1 times the nominal first interior area width dimension, and each nominal second-track generating trace width dimension is at least 0.1 times the nominal second interior area width dimension; the field generating coil configuration further comprises at least one shielded end portion that extends generally along the y-axis direction and connects to at least one elongated portion that is nominally located at an elongated portion z distance from a front surface of the detector portion that faces the scale pattern, along a z axis direction that is perpendicular to the x-axis and y-axis directions, wherein that shielded end portion comprises; a shielded end section that is nominally located at a shielded end section z distance from the front surface of the detector portion, wherein the shielded end section z distance is greater than the elongated portion z distance; and the detector portion further comprises a conductive shield region extending along the x-axis and y-axis directions and nominally located at a shield region z distance from the front surface, wherein the shield region z distance is smaller than the shielded end section z distance, and the shield region is located between at least part of the shielded end section and the front surface of the detector portion. - View Dependent Claims (16, 17, 18, 19, 20)
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21. A measurement system configured to operate in conjunction with a scale, the scale extending along a measuring axis direction that coincides with an x-axis direction and including a signal modulating scale pattern comprising first and second pattern tracks arranged parallel to one another, each pattern track having a track width dimension along a y-axis direction that is perpendicular to the x-axis direction between its interior boundary that is closest to the other pattern track and its exterior boundary that is farthest from the other pattern track, and each pattern track comprising signal modulating elements that are arranged to provide a spatially varying characteristic which changes as a periodic function of position along the x-axis direction, the measurement system comprising:
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a detector portion configured to be mounted proximate to the pattern tracks and to move along the measuring axis direction relative to the pattern tracks, the detector portion comprising; a field generating coil configuration fixed on a substrate, comprising; a first-track field generating coil portion comprising first-track inside and outside elongated portions, the first-track field generating coil portion surrounding a first interior area aligned with the first pattern track and having a nominal first interior area length dimension along the x-axis direction and a nominal first interior area width dimension along the y-axis direction, the nominal first interior area width dimension extending from the first-track inside elongated portion to the first-track outside elongated portion, the first-track field generating coil portion generating a changing first magnetic flux in the first interior area in response to a coil drive signal, and a second-track field generating coil portion comprising second-track inside and outside elongated portions, the second-track field generating coil portion surrounding a second interior area aligned with the second pattern track and having a nominal second interior area length dimension along the x-axis direction and a nominal second interior area width dimension along the y-axis direction, the nominal second interior area width dimension extending from the second-track inside elongated portion to the second-track outside elongated portion, the second-track field generating coil portion generating a changing magnetic flux in the second interior area in response to the coil drive signal; and a plurality of sensing elements arranged along the x-axis direction and fixed on the substrate, each of the sensing elements having a nominal sensing element width dimension along the y-axis direction that spans the first and second interior areas, wherein the plurality of sensing elements are configured to provide detector signals which respond to a local effect on the changing magnetic flux provided by adjacent signal modulating elements of the scale pattern; and a signal processing configuration that is operably connected to the detector portion to provide the coil drive signal and that determines the relative position between the detector portion and the scale pattern based on detector signals input from the detector portion, wherein; the field generating coil configuration comprises; an input portion comprising at least two connection portions that connect the coil drive signal from the signal processing configuration to the field generating coil configuration; the first-track inside and outside elongated portions extending along the x-axis direction adjacent to the first interior area, the first-track inside elongated portion located adjacent to the first-track interior boundary and the first-track outside elongated portion located adjacent to the first-track exterior boundary, the first-track inside and outside elongated portions each comprising a conductive trace having a nominal first-track generating trace width dimension along the y-axis direction; and the second-track inside and outside elongated portions extending along the x-axis direction adjacent to the second interior area, the second-track inside elongated portion located adjacent to the second-track interior boundary and the second-track outside elongated portion located adjacent to the second-track exterior boundary, the second-track inside and outside elongated portions each comprising a conductive trace having a nominal second-track generating trace width dimension along the y-axis direction; at least a majority of the nominal sensing element width dimension is included between the first-track outside elongated portion and the second-track outside elongated portion, and the field generating coil configuration is configured such that each nominal first-track generating trace width dimension is at least 0.1 times the nominal first interior area width dimension, and each nominal second-track generating trace width dimension is at least 0.1 times the nominal second interior area width dimension.
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Specification