Position sensing using coil sensor
First Claim
1. A printed circuit board (PCB), comprising:
- a substrate that is non-conductive; and
an asymmetric coil, formed on the substrate, the asymmetric coil having a plurality of coil loops that are conductive and asymmetric with respect to an axis transverse to a longitudinal axis of the asymmetric coil;
a first distance between adjacent coil loops crossing the longitudinal axis on a first transverse side of a center of an innermost coil loop being substantially equal, anda second distance between the adjacent coil loops crossing the longitudinal axis on a second transverse side of the center of the innermost coil loop opposite to the first transverse side of the center of the innermost coil loop being larger than the first distance, the second distance increasing with each successively outward coil loop; and
wherein the asymmetric coil is coupleable to receive an excitation signal and in response to project a time-varying asymmetric magnetic field.
1 Assignment
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Accused Products
Abstract
A printed circuit board (PCB). The PCB comprises a non-conductive substrate and a plurality of conductive coil loops formed on the substrate, wherein the coil loops are asymmetric. The conductive coil loops are formed as a continuous metal trace on the substrate, the coil loops are symmetric with reference to a longitudinal axis of the PCB, the coil loops are asymmetric with reference to an axis transverse to the longitudinal axis of the PCB, wherein the distance between adjacent coil loops crossing the longitudinal axis on a first side of a center of an innermost coil loop are substantially equal, and the distance between adjacent coil loops crossing the longitudinal axis on a side of the center of the innermost coil loop opposite to the first side of the center of the innermost coil loop increase with each coil loop progressing outwards.
23 Citations
18 Claims
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1. A printed circuit board (PCB), comprising:
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a substrate that is non-conductive; and an asymmetric coil, formed on the substrate, the asymmetric coil having a plurality of coil loops that are conductive and asymmetric with respect to an axis transverse to a longitudinal axis of the asymmetric coil; a first distance between adjacent coil loops crossing the longitudinal axis on a first transverse side of a center of an innermost coil loop being substantially equal, and a second distance between the adjacent coil loops crossing the longitudinal axis on a second transverse side of the center of the innermost coil loop opposite to the first transverse side of the center of the innermost coil loop being larger than the first distance, the second distance increasing with each successively outward coil loop; and wherein the asymmetric coil is coupleable to receive an excitation signal and in response to project a time-varying asymmetric magnetic field. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A position sensor, comprising:
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an asymmetric coil comprising a plurality of coil loops that are conductive, and asymmetric with respect to an axis transverse to a longitudinal axis of the asymmetric coil; a first distance between adjacent coil loops crossing the longitudinal axis on a first transverse side of a center of an innermost coil loop being substantially equal, and a second distance between the adjacent coil loops crossing the longitudinal axis on a second transverse side of the center of the innermost coil loop opposite to the first transverse side of the center of the innermost coil loop being larger than the first distance, the second distance increasing with each successively outward coil loop; and a transducer coupled to the asymmetric coil, wherein the transducer is configured to provide an excitation signal to the asymmetric coil to project a time-varying asymmetric magnetic field, to determine a response of the asymmetric coil to the excitation signal and to determine an output signal based on a response of the asymmetric coil to a lateral position of a target relative to the asymmetric coil. - View Dependent Claims (9, 10, 11, 12, 17)
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13. A method of determining position of an object, comprising:
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exciting an asymmetric coil with an alternating current signal, the asymmetric coil formed with a plurality of coil loops that are conductive, and asymmetric with respect to an axis transverse to a longitudinal axis of the asymmetric coil; a first distance between adjacent coil loops crossing the longitudinal axis on a first transverse side of a center of an innermost coil loop being substantially equal, and a second distance between the adjacent coil loops crossing the longitudinal axis on a second transverse side of the center of the innermost coil loop opposite to the first transverse side of the center of the innermost coil loop being larger than the first distance, the second distance increasing with each successively outward coil loop; projecting a time-varying asymmetric magnetic field by the asymmetric coil; inducing eddy currents in a target that is electrically conductive, by action of the time-varying asymmetric magnetic field, wherein an amplitude of the eddy currents is determined by a lateral position of the target relative to the asymmetric coil; determining an inductance of the asymmetric coil, wherein the inductance of the asymmetrical coil varies in part based on the eddy currents induced in the target; and determining the lateral position of the target based on the inductance of the asymmetric coil. - View Dependent Claims (14, 15, 16, 18)
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Specification