System for capacitive object detection
AssigneeIee International Electronics & Engineering S.A.
InventorLaurent Lamesch
Life of this patent
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Abstract
A system for capacitive object detection. In order to provide means for efficiently using the circuitry of an electrical heating device for capacitive object detection, the system includes: an elongate conductive element extending between a first terminal and a second terminal, wherein the first terminal is coupled to ground via a capacitive element and is connectable to an electrical power source, and the second terminal is connected to ground; and a detection circuit connected to at least one detection node disposed on the conductive element between the first and second terminal. The detection circuit is adapted to capacitively detect the presence of an object in the proximity of the conductive element based on an impedance associated with the object.
Claims20
A system for capacitive object detection, comprising:
- an elongate conductive element extending between a first terminal and a second terminal, wherein the first terminal is coupled to ground via a first capacitive element and is connectable to an electrical power source, and the second terminal is connected to ground;
- and
- a detection circuit connected to at least one detection node disposed on the conductive element between the first and second terminal;
- wherein the detection circuit is adapted to capacitively detect the presence of an object in the proximity of the conductive element based on a impedance associated with the object, the detection circuit being configured to operate at least one detection node in a loading mode, in which the detection circuit applies a detection signal to the at least one detection node and detects the object based on a response signal at the detection node;
- wherein the detection circuit is configured to operate at least one detection node in a transmitting mode, in which the detection circuit applies a transmission signal to the at least one detection node, and to detect the object based on a received signal from at least one receiving unit;
- and
- wherein the detection circuit is adapted to sequentially and/or simultaneously apply two different frequencies as the detection signal to the at least one detection node and to detect the object based on a frequency-dependent response signal.
A system for capacitive object detection, comprising:
- an elongate conductive element extending between a first terminal and a second terminal, wherein the first terminal is coupled to ground via a first capacitive element and is connectable to an electrical power source, and the second terminal is connected to ground;
- and
- a detection circuit connected to at least one detection node disposed on the conductive element between the first and second terminal;
- wherein the detection circuit is adapted to capacitively detect the presence of an object in the proximity of the conductive element based on a impedance associated with the object, the detection circuit being configured to operate at least one detection node in a loading mode, in which the detection circuit applies a detection signal to the at least one detection node and detects the object based on a response signal at the detection node;
- wherein the detection circuit is configured to operate at least one detection node in a receiving mode, in which the detection circuit detects the object based on a received signal from the at least one detection node in response to a transmission signal applied to at least one transmitting unit;
- and
- wherein the detection circuit is adapted to sequentially and/or simultaneously apply two different frequencies as the detection signal to the at least one detection node and to detect the object based on a frequency-dependent response signal.
Dependencies are inferred from the claim text.