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- Nachgewiesen in: USPTO Patent Applications
- Sprachen: English
- Document Number: 20190302304
- Publication Date: October 3, 2019
- Appl. No: 16/469571
- Application Filed: November 23, 2017
- Claim: 1. A device for detecting an object with respect to a detection surface, said device comprising: at least one measurement electrode; at least one electrode, called guard electrode; a measurement electronics for measuring a signal with respect to the electrical capacitance of said measurement electrode; said measurement and guard electrodes are separated by a distance (D) that is elastically modifiable locally, by a load exerted by said object on said detection surface; and means for electrical polarization of the electrodes arranged in order to: apply to the measurement and guard electrodes: one and the same first alternating electrical potential (Vg), or first, substantially identical, alternating potentials; that is(are) different from a ground potential (G), so as to measure a first signal with respect to the capacitance (Ceo), called electrode-object capacitance, between said measurement electrode and said object; apply between the measurement and guard electrodes an alternating electrical potential difference (V1), so as to measure a second signal with respect to the capacitance (Ceg), called electrode-guard capacitance, between said electrodes.
- Claim: 2. The device according to claim 1, characterized in that the means for electrical polarization of the electrodes are arranged so as to generate a first alternating electrical potential (Vg) and an electrical potential difference (V1) satisfying at least one of the following criteria: the first alternating electrical potential (Vg) and the electrical potential difference (V1) comprise respectively at least one frequency component at a different frequency; the first alternating electrical potential (Vg) and the electrical potential difference (V1) comprise signals that are orthogonal to one another.
- Claim: 3. The device according to claim 1, characterized in that it comprises measurement electronics with at least one demodulation means utilizing at least one of the following elements: a synchronous demodulator; an amplitude detector; and a digital demodulator.
- Claim: 4. The device according to claim 3, characterized in that it comprises a first demodulation means exploiting the first alternating electrical potential (Vg) in order to determine the first signal, and a second demodulation means exploiting the alternating electrical potential difference (V1) in order to determine the second signal.
- Claim: 5. The device according claim 1, characterized in that the means for electrical polarization of the electrodes are arranged in order to generate an alternating electrical potential difference (V1) with an amplitude different from the amplitude of the first alternating electrical potential (Vg).
- Claim: 6. The device according to claim 1, characterized in that the means for electrical polarization of the electrodes comprise a first electrical source (E) referenced at an input to the ground potential (G) and supplying the first alternating electrical potential (Vg).
- Claim: 7. The device according to claim 6, characterized in that the first electrical source (E) is electrically connected at an output to the at least one guard electrode, the means for electrical polarization of the electrodes also comprising a first source switch making it possible to electrically polarize the at least one measurement electrode either at the first alternating electrical potential (Vg) or at the ground potential (G).
- Claim: 8. The device according claim 1, characterized in that the means for electrical polarization of the electrodes comprise a second electrical source (V) supplying between its terminals the alternating electrical potential difference (V1), said second voltage source (V) being referenced at the input to the first alternating electrical potential (Vg), and being arranged at the output according to one of the following configurations: so as to apply the alternating electrical potential difference (V1) to the at least one guard electrode; and so as to apply the alternating electrical potential difference (V1 ) to the at least one measurement electrode.
- Claim: 9. The device according to claim 1, characterized in that the means for electrical polarization of the electrodes comprise at least one of the following switches: a first switch arranged so as to make it possible to apply to the at least one guard electrode and to the at least one measurement electrode, either the ground potential (G) or the first alternating electrical potential (Vg); and a second switch arranged so as to make it possible to apply between the at least one guard electrode and the at least one measurement electrode, either the alternating electrical potential difference (V1), or a zero or substantially zero potential difference.
- Claim: 10. The device according to claim 1, characterized in that it comprises at least one calculation module configured in order to: determine a distance or a contact between the object and the detection surface as a function of the first signal; and/or - determine a load or a pressure applied by said object on the detection surface as a function of the second signal.
- Claim: 11. The device according to claim 1, characterized in that it comprises at least one measurement electrode and at least one guard electrode separated by a layer that is elastically compressible, comprising or formed by a dielectric material.
- Claim: 12. The device according to claim 1, characterized in that it comprises at least one measurement electrode placed on, or in, or under, a support, produced from a flexible material, such as a fabric, placed above and at a distance from at least one guard electrode, and deforming at least locally when a load is exerted on said support.
- Claim: 13. The device according to claim 1, characterized in that it comprises several measurement electrodes.
- Claim: 14. The device according to claim 13, characterized in that it comprises one or more guard electrodes arranged according to at least one of the following configurations: at least one guard electrode, placed opposite several, in particular all, the measurement electrodes; for at least one, in particular each, measurement electrode, a guard electrode placed opposite said measurement electrode ; and for at least one, in particular each, measurement electrode, several guard electrodes placed opposite said measurement electrode.
- Claim: 15. The device according to claim 1, characterized in that it also comprises at least one second guard electrode polarized at a potential identical to the potential of the measurement electrode or electrodes.
- Claim: 16. The device according to claim 1, characterized in that it comprises several measurement electrodes, and an electrode switch making it possible to selectively connect a measurement electrode, called “active electrode”, to the measurement electronics, said electrode switch also being arranged in order to polarize the other measurement electrodes at the same electrical potential as the active electrode.
- Claim: 17. The device according to claim 13, comprising a second electrical source (V) arranged so as to apply the alternating electrical potential difference (V1) to a plurality of guard electrodes, characterized in that it also comprises a guard electrode switch making it possible to selectively connect one or a plurality of guard electrodes, called “excited guard electrode or electrodes”, to the second voltage source (V), said electrode switch also being arranged in order to polarize the other guard electrodes at the same electrical potential as the active electrode.
- Claim: 18. The device according to claim 1, characterized in that the measurement electronics comprise a circuit utilizing an operational amplifier with an impedance comprising a feedback capacitive component, the measurement electrode or electrodes being connected to the negative input of said operational amplifier.
- Claim: 19. The device according to claim 18, characterized in that the circuit utilizing an operational amplifier is supplied by an electrical supply referenced to the first alternating electrical potential (Vg).
- Claim: 20. A method for the detection of an object with respect to a detection surface utilizing a detection device according to claim 1, said method comprising at least one iteration of the following steps: a first step of detecting the approach and/or contact of the object with respect to said detection surface comprising the following operations: application to the measurement and guard electrodes: of one and the same first alternating electrical potential (Vg), or first alternating potentials that are substantially identical; that is(are) different from a ground potential (G); measuring a first signal with respect to the capacitance (Ceo), called electrode-object capacitance, between said measurement electrode and said object; a second step of detecting pressure of said object on said detection surface comprising the following operations: applying, between the measurement and guard electrodes, an alternating electrical potential difference (V1); and measuring a second signal with respect to the capacitance (Ceg), called electrode-guard capacitance, between said measurement and guard electrodes.
- Claim: 21. The method according to claim 20, characterized in that the detection device comprises a plurality of measurement electrodes, the second detection step being carried out only in an area of the detection surface in which the object was detected during the first detection step.
- Claim: 22. The method according to claim 20, characterized in that it comprises a calibration step comprising: detecting approach and/or contact; in the absence of a detected object, detecting pressure so as to determine an electrode-guard capacitance called “calibration capacitance”.
- Claim: 23. The method according to claim 22, characterized in that it comprises a step of functional verification comprising a comparison of an electrode-guard calibration capacitance with a nominal electrode-guard capacitance or a range of nominal electrode-guard capacitances.
- Claim: 24. A detection layer, for an item of equipment, equipped with a device according to claim 1.
- Claim: 25. An item of equipment, equipped with a detection device according to claim 1.
- Current International Class: 01
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