Capacitive sensor with orthogonal fields
First Claim
1. A proximity sensor comprising:
- a first pair of electrodes aligned along a first axis;
a second pair of electrodes aligned along a second axis substantially perpendicular to the first axis;
a signal generator configured to apply a first signal across the first pair of electrodes to produce a first electric field and to apply a second signal across the second pair of electrodes to produce a second electric field that is substantially perpendicular to the first electric field, wherein the first and second electric fields are produced concurrently;
a detector configured to concurrently detect a first change in the first signal due to an object interacting with the first electric field and a second change in the second signal due to the object interacting with the second electric field; and
a comparator configured to determine a distance of the object from the first and second pair of electrodes based on a ratio of the first and second changes.
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Accused Products
Abstract
A method and system for determining a distance from a probe to an object includes generating a first electric field by applying a first signal across a first pair of electrodes aligned along a first axis and generating a second electric field by applying a second signal across a second pair of electrodes aligned along a second axis substantially perpendicular to the first axis. After generating the signals, a first change in the first signal due to the object interacting with the first electric field and a second change in the second signal due to the object interacting with the second electric field is concurrently detected. A distance of the object from the first and second pair of electrodes can be calculated based on a ratio of the first and second changes.
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Citations
20 Claims
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1. A proximity sensor comprising:
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a first pair of electrodes aligned along a first axis; a second pair of electrodes aligned along a second axis substantially perpendicular to the first axis; a signal generator configured to apply a first signal across the first pair of electrodes to produce a first electric field and to apply a second signal across the second pair of electrodes to produce a second electric field that is substantially perpendicular to the first electric field, wherein the first and second electric fields are produced concurrently; a detector configured to concurrently detect a first change in the first signal due to an object interacting with the first electric field and a second change in the second signal due to the object interacting with the second electric field; and a comparator configured to determine a distance of the object from the first and second pair of electrodes based on a ratio of the first and second changes. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for determining a distance from a probe to an object, comprising:
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generating a first electric field by applying a first signal across a first pair of electrodes aligned along a first axis; generating, concurrently with the first electric field, a second electric field by applying a second signal across a second pair of electrodes aligned along a second axis substantially perpendicular to the first axis, wherein the first electric field is substantially perpendicular to the second electric field; concurrently detecting a first change in the first signal due to the object interacting with the first electric field and a second change in the second signal due to the object interacting with the second electric field; and calculating a distance of the object from the first and second pair of electrodes based on a ratio of the first and second changes. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A capacitive probe comprising:
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a sensor body upper surface; a first electrode located on the sensor body upper surface, the first electrode having a first top portion extending above the sensor body upper surface and a first bottom portion, opposite the first top portion, configured for electrical communication with a first electromagnetic signal; a second electrode located on the sensor body upper surface, the second electrode having a second top portion extending above the sensor body upper surface and a second bottom portion, opposite the second top portion, configured for electrical communication with the first electromagnetic signal, wherein the first and second electrodes are aligned along a first axis; a third electrode located on the sensor body upper surface, the third electrode having a third top portion extending above the sensor body upper surface and a third bottom portion, opposite the third top portion, configured for electrical communication with a second electromagnetic signal; and a fourth electrode located on the sensor body upper surface, the fourth electrode having a fourth top portion extending above the sensor body upper surface and a fourth bottom portion, opposite the fourth top portion, configured for electrical communication with the second electromagnetic signal, wherein the third and fourth electrodes are aligned along a second axis substantially perpendicular to the first axis. - View Dependent Claims (20)
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Specification