Induced current position transducers having improved scale loop structures
AssigneeMitutoyo Corporation
InventorMichelle M. Milvich
Life of this patent
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Abstract
A scale loop formed by a loop trace of electrically conductive material is usable in an induced current position transducer. The scale loop is continuous and has a particular shape depending on the configuration of the induced current position transducer. The scale loop is not in contact with other highly conductive materials. The dimensions of the cross-section of the conducting trace are chosen to increase the transfer of energy through the transducer.
Claims27
A scale loop of an induced current position transducer, the scale loop comprising an interior area bounded by a conductive scale trace, the scale loop positionable along a measuring axis relative to an inductive position transducer readhead such that a first portion of the interior area overlies a magnetic field generating region on the readhead and a second portion of the interior area overlies a magnetic field sensing region on the readhead, each of the first and second portions having a set of characteristic dimensions comprising:
- a maximum dimension parallel to the measuring axis;
- and
- a maximum dimension transverse to the measuring axis;
- wherein at least a portion of the scale loop trace has a width dimension that is at least about 0.2 times the least of the characteristic dimensions.
A scale loop of an induced current position transducer, comprising:
- a scale trace formed from an electrically conductive material, the scale trace fixed on a substrate, wherein:
- the scale trace is arranged in a continuous loop;
- and
- the scale trace has a maximum cross-sectional thickness between a top surface and a bottom surface of the scale trace along a direction approximately normal to the substrate, the maximum cross-sectional thickness at any point along the scale trace being at most 0.8 skin depths of the material at a frequency of operation of the induced current position transducer.
A scale loop of an induced current position transducer, the scale loop comprising an interior area bounded by a conductive scale trace fixed on a substrate, the scale loop positionable along a measuring axis relative to an inductive position transducer readhead such that a first portion of the interior area overlies a magnetic field generating region on the readhead and a second portion of the interior area overlies a magnetic field sensing region on the readhead, each of the first and second portions having a set of characteristic dimensions comprising:
- a maximum dimension parallel to the measuring axis;
- and
- a maximum dimension transverse to the measuring axis;
- wherein the conductive scale trace has a cross-section that has a significant thickness in a direction normal to the substrate in comparison to its width parallel to the substrate;
- and at least a portion of the scale trace has a cross-sectional perimeter that is at least about 0.4 times the least of the characteristic dimensions.
A scale loop of an induced current position transducer, the scale loop comprising an interior area bounded by a scale trace formed from a conductive material fixed on a substrate, the scale loop positionable along a measuring axis relative to an inductive position transducer readhead such that a first portion of the interior area overlies a magnetic field generating region on the readhead and a second portion of the interior area overlies a magnetic field sensing region on the readhead, each of the first and second portions having a set of characteristic dimensions comprising:
- a maximum dimension parallel to the measuring axis;
- and
- a maximum dimension transverse to the measuring axis;
- (a) at least a portion of the scale trace has a width dimension that is at least about 0.2 times the least of the characteristic dimensions and the scale trace has a cross-sectional thickness between a top surface and a bottom surface of the scale trace along the direction normal to the substrate, a maximum cross-sectional thickness at any point along the scale trace is approximately equal to or less than 3 skin depths of the material at a frequency of operation of the induced current position transducer;
- and
- (b) at least a portion of the scale trace has a cross-sectional perimeter that is at least about 0.4 times the least of the characteristic dimensions and the scale trace has a cross-section that has a significant thickness in a direction normal to the substrate in comparison to its width parallel to the substrate.
A scale loop of an induced current position transducer, the scale loop comprising an interior area bounded by a scale trace formed from an electrically conductive material, the scale loop positionable along a measuring axis relative to an inductive position transducer readhead such that a first portion of the interior area overlies a magnetic field generating region on the readhead and a second portion of the interior area overlies a magnetic field sensing region on the readhead, each of the first and second portions having a set of characteristic dimensions comprising:
- a maximum dimension parallel to the measuring axis;
- and
- a maximum dimension transverse to the measuring axis;
- wherein:
- at least a section of the scale loop trace has a width dimension that is at least about 0.2 times the least of the characteristic dimensions;
- and
- the scale trace has a maximum cross-sectional thickness between a top surface and a bottom surface of the scale trace along a direction approximately normal to the substrate, the maximum cross-sectional thickness at any point along the scale trace being approximately equal to or less than 3 skin depths of the material at a frequency of operation of the induced current position transducer.
Dependencies are inferred from the claim text.