DATA GATHERING SYSTEM
First Claim
1. Apparatus for gathering data, the apparatus comprising:
- a first electrode, the electrode characterized as non-sticky, the electrode disposed for capacitive or electrically conductive coupling with a surface;
a second electrode, the electrode characterized as non-sticky, the electrode disposed for capacitive or electrically conductive coupling with a region opposed to the surface;
electronic circuitry disposed between the first and second electrodes;
the first electrode shielded by a shield located between the first electrode and the electronic circuitry;
the second electrode shielded by a shield located between the second electrode and the electronic circuitry;
the electronic circuitry comprising a first driver and a first amplifier receiving as an input a signal present at the first electrode, the first driver having an output coupled with the shield of the first electrode;
the electronic circuitry comprising a second driver and a second amplifier receiving as an input a signal present at the second electrode, the second driver having an output coupled with the shield of the second electrode;
the electronic circuitry further comprising a differential amplifier having first and second inputs, the first and second inputs connected to outputs of the first and second amplifiers, respectively;
the differential amplifier having an output;
the electronic circuitry further comprising means for communicating data indicative of the output of the differential amplifier to equipment external to the apparatus.
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Accused Products
Abstract
A device for gathering data has first and second electrodes. The first electrode is coupled to a surface of interest, and the second electrode is coupled to “everything else” or “the air”. The first electrode is shielded from the second, and from most sources of parasitic capacitance, by a shield that is driven by an active driver that drives the shield to track, and ideally to match, the instantaneous potential of the electrode. The second electrode is likewise shielded in a similar way from most sources of parasitic capacitance. These shields likewise help to limit the extent to which RFI from the device electronics couples with either of the electrodes. In this way the sensing device achieves a markedly better signal-to-noise ratio at frequency bands of interest.
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Citations
12 Claims
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1. Apparatus for gathering data, the apparatus comprising:
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a first electrode, the electrode characterized as non-sticky, the electrode disposed for capacitive or electrically conductive coupling with a surface; a second electrode, the electrode characterized as non-sticky, the electrode disposed for capacitive or electrically conductive coupling with a region opposed to the surface; electronic circuitry disposed between the first and second electrodes; the first electrode shielded by a shield located between the first electrode and the electronic circuitry; the second electrode shielded by a shield located between the second electrode and the electronic circuitry; the electronic circuitry comprising a first driver and a first amplifier receiving as an input a signal present at the first electrode, the first driver having an output coupled with the shield of the first electrode; the electronic circuitry comprising a second driver and a second amplifier receiving as an input a signal present at the second electrode, the second driver having an output coupled with the shield of the second electrode; the electronic circuitry further comprising a differential amplifier having first and second inputs, the first and second inputs connected to outputs of the first and second amplifiers, respectively; the differential amplifier having an output; the electronic circuitry further comprising means for communicating data indicative of the output of the differential amplifier to equipment external to the apparatus. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for use in detecting signals, the method comprising the steps of:
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providing a first electrode, the electrode characterized as non-sticky, the electrode capacitively or electrically conductively with a surface; providing a second electrode, the electrode characterized as non-sticky, the electrode capacitively coupled with a region opposed to the surface; providing an electroninc circuitry between the first electrode and the second electrode; providing a first shield between the first electrode and the electronic circuitry; providing a second shield between the second electrode and the electronic circuitry; driving the first shield to follow a signal present at the first electrode; driving the second shield to follow a signal present at the second electrode; deriving a difference between the signal present at the first electrode and the signal present at the second electrode; and communicating data indicative of the difference to equipment external to the apparatus, wherein the electronic circuitry comprises a first driver and a first amplifier receiving as an input a signal present at the first electrode, the first driver having an output coupled with the shield of the first electrode, the electronic circuitry comprises a second driver and a second amplifier receiving as an input a signal present at the second electrode, the second driver having an output coupled with the shield of the second electrode, the electronic circuitry further comprises a differential amplifier having first and second inputs, the first and second inputs connected to outputs of the first and second amplifiers, respectively, and the differential amplifier has an output indicating the difference. - View Dependent Claims (9, 10, 11, 12)
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Specification