Proximity sensor
First Claim
1. A proximity sensor for sensing an electric-field-influencing media within a region of space, comprising:
- a. a first electrode, wherein said first electrode is conductive;
b. a first oscillatory signal operatively connected to said first electrode;
c. at least one second electrode separated from and located proximate to said first electrode so that an electric field between said first electrode and said at least one second electrode occupies said region of space, wherein said electric field is responsive to said first oscillatory signal, and said at least one second electrode is conductive;
d. at least one second oscillatory signal operatively connected to said at least one second electrode, wherein said at least one second oscillatory signal is coherent with said first oscillatory signal, and said at least one second oscillatory signal comprises a plurality of second signal components each selected from the group consisting of a signal level and a signal phase relative to a phase of said first oscillatory signal, wherein each signal component is at a distinct time; and
e. a circuit operatively connected to said first electrode, wherein said circuit senses a third signal from said first electrode, wherein said third signal comprises a plurality of third signal components, said third signal is responsive to said first oscillatory signal, said third signal is responsive to said at least one second oscillatory signal, said third signal is responsive to a proximity to said first electrode of the electric-field-influencing media, said third signal is selected from the group consisting of a current of said first oscillatory signal, a voltage of said first oscillatory signal, and a capacitance of said first electrode, respective third signal components are respectively responsive to respective signal components of said plurality of second signal components applied to said at least one second electrode, and said circuit generates from said plurality of third signal components a measure of the proximity of the electric-field-influencing media to said first electrode.
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Accused Products
Abstract
A sense electrode (12) and a plurality of control electrodes (14) are located proximate to a region of space (18) for sensing an object (20) therein. A first signal (26) and a plurality of second signals (30) respectively applied to the sense (12) and control (14) electrodes generate an electric field (16) within the region of space (18). The capacitance of the sense electrode (12) is measured for various electric field configurations responsive to the second signals (30) and to the proximity of the object (20). A most likely proximity scenario from a priori proximity scenarios is determined from the plurality of capacitance measurements. A front driven shield (36) is provided between the sense electrode (12) and the region of space (18) for selectively shielding the sense electrode (12) from influence by objects (20) or grounds, so as to provide for calibrating the measurement circuit (32) to compensate for parasitic capacitance and gain drift.
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Citations
26 Claims
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1. A proximity sensor for sensing an electric-field-influencing media within a region of space, comprising:
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a. a first electrode, wherein said first electrode is conductive;
b. a first oscillatory signal operatively connected to said first electrode;
c. at least one second electrode separated from and located proximate to said first electrode so that an electric field between said first electrode and said at least one second electrode occupies said region of space, wherein said electric field is responsive to said first oscillatory signal, and said at least one second electrode is conductive;
d. at least one second oscillatory signal operatively connected to said at least one second electrode, wherein said at least one second oscillatory signal is coherent with said first oscillatory signal, and said at least one second oscillatory signal comprises a plurality of second signal components each selected from the group consisting of a signal level and a signal phase relative to a phase of said first oscillatory signal, wherein each signal component is at a distinct time; and
e. a circuit operatively connected to said first electrode, wherein said circuit senses a third signal from said first electrode, wherein said third signal comprises a plurality of third signal components, said third signal is responsive to said first oscillatory signal, said third signal is responsive to said at least one second oscillatory signal, said third signal is responsive to a proximity to said first electrode of the electric-field-influencing media, said third signal is selected from the group consisting of a current of said first oscillatory signal, a voltage of said first oscillatory signal, and a capacitance of said first electrode, respective third signal components are respectively responsive to respective signal components of said plurality of second signal components applied to said at least one second electrode, and said circuit generates from said plurality of third signal components a measure of the proximity of the electric-field-influencing media to said first electrode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A proximity sensor for sensing an electric-field-influencing media within a region of space, comprising:
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a) a first electrode having a first side and a second side, wherein said first electrode is conductive and said first electrode is disposed along a first surface;
b) a first oscillatory signal operatively connected to said first electrode; and
c) a third electrode, wherein said third electrode is conductive, said third electrode is disposed along a second surface, said third electrode is proximate to and insulated from said first side of said first electrode between said first side of said first electrode and said region, and in a shielding mode said third electrode is operatively connected to said first oscillatory signal. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A method of sensing the proximity of an electric-field-influencing media within a region of space, comprising:
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a) applying a first oscillatory signal to a first electrode;
b) applying at least one second oscillatory signal to a respective at least one second electrode, wherein said at least one second oscillatory signal comprises a plurality of second signal components each selected from the group consisting of a signal level and a signal phase relative to a phase of said first oscillatory signal, wherein each signal component is applied at a distinct time;
c) sensing a third signal from said first electrode, wherein said third signal comprises a plurality of third signal components, each respective said third signal component is responsive to a different respective second signal component, wherein said third signal is selected from the group consisting of a current of said first oscillatory signal, a voltage of said first oscillatory signal, and a capacitance of said first electrode; and
d) generating from said plurality of third signal components a measure of the proximity of an electric-field-influencing media to said first electrode. - View Dependent Claims (20, 21)
a) generating a plurality of measures from said plurality of third signal components;
b) establishing a plurality of proximity scenarios, wherein each proximity scenario comprises a different proximity of the electric-field-influencing media to said first electrode;
c) generating a plurality of likelihoods from said plurality of measures, wherein each respective likelihood of said plurality of likelihoods is the likelihood of a corresponding respective proximity scenario of said plurality of proximity scenarios; and
d) selecting a most likely proximity scenario from said plurality of proximity scenarios, wherein the operation of selecting is responsive to said plurality of likelihoods.
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22. A method of sensing the proximity of an electric-field-influencing media within a region of space, comprising:
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a) applying a first oscillatory signal to a first electrode, wherein said first electrode has a first side and a second side;
b) in a shielding mode, applying said first oscillatory signal to a third electrode, wherein said third electrode is located between said first side of said first electrode and the region of space; and
c) in a sensing mode, sensing a signal from said first electrode responsive to the proximity of the electric-field-influencing media to said first electrode, wherein said sensing mode and said shielding mode are mutually exclusive. - View Dependent Claims (23, 24, 25)
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26. A method of sensing the proximity of an electric-field-influencing media within a region of space, comprising:
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a) generating an electric field in the region of space by applying a first signal to a first electrode and by applying at least one second signal to a respective at least one second electrode;
b) measuring a third signal from said first electrode, wherein said third signal is responsive to at least one element selected from the group consisting of said first signal, said at least one second signal, a geometry of said first electrode, and a geometry of said at least one second electrode;
c) making at least one modification to said at least one second signal so as to modify said electric field;
d) measuring said third signal for each said at least one modification to said at least one second signal;
e) generating a measure of proximity of an electric-field-influencing media within the region of space from the measurements of said third signal.
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Specification