Capacitance scanning proximity detection
First Claim
Patent Images
1. A method comprising:
- scanning, by a processing device, a first set of electrodes in a first dimension of a capacitive sense array to measure self-capacitances of the first set of electrodes, using a first dimension multiplexer to route measured signals from the first set of electrodes to receive channels of the processing device, wherein a shield signal is routed through a second dimension multiplexer to a second set of electrodes in a second dimension;
identifying, based on the measured self-capacitances of the first set of electrodes, the presence of an object in proximity to the first set of electrodes and the capacitive sense array and not in physical contact with the capacitive sense array;
responsive to identifying the presence of the object based on the measured self-capacitances of the first set of electrodes, configuring the capacitive sense array to measure a mutual capacitance of at least the first set of electrodes and the second set of electrodes by routing a transmit signal through the first dimension multiplexer to the first set of electrodes and routing measured signals from the second set of electrodes to the receive channels of the processing device; and
scanning, by the processing device, the first set of electrodes and the second set of electrodes of the capacitive sense array to measure mutual capacitances of intersections between the first set of electrodes and the second set of electrodes to determine a location of the object.
6 Assignments
0 Petitions
Accused Products
Abstract
A method and apparatus for scanning a first set of electrodes of a capacitive sense array using a first sensing mode to identify a presence of an object in proximity to the capacitive sense array, where scanning using the first sensing mode identifies objects not in physical contact with the capacitive sense array. The first set of electrodes is scanned using a second sensing mode to determine a location of the object in relation to the capacitive sense array, where rescanning using the second sensing mode determines locations of objects in physical contact with the capacitive sense array.
145 Citations
16 Claims
-
1. A method comprising:
-
scanning, by a processing device, a first set of electrodes in a first dimension of a capacitive sense array to measure self-capacitances of the first set of electrodes, using a first dimension multiplexer to route measured signals from the first set of electrodes to receive channels of the processing device, wherein a shield signal is routed through a second dimension multiplexer to a second set of electrodes in a second dimension; identifying, based on the measured self-capacitances of the first set of electrodes, the presence of an object in proximity to the first set of electrodes and the capacitive sense array and not in physical contact with the capacitive sense array; responsive to identifying the presence of the object based on the measured self-capacitances of the first set of electrodes, configuring the capacitive sense array to measure a mutual capacitance of at least the first set of electrodes and the second set of electrodes by routing a transmit signal through the first dimension multiplexer to the first set of electrodes and routing measured signals from the second set of electrodes to the receive channels of the processing device; and scanning, by the processing device, the first set of electrodes and the second set of electrodes of the capacitive sense array to measure mutual capacitances of intersections between the first set of electrodes and the second set of electrodes to determine a location of the object. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. An apparatus comprising:
-
a capacitive sense array comprising a plurality of electrodes, including a first set of electrodes in a first dimension and a second set of electrodes in a second dimension; a first dimension multiplexer coupled to the first set of electrodes; a second dimension multiplexer coupled to the second set of electrodes; and a processing device coupled to the capacitive sense array through the first dimension multiplexer and the second dimension multiplexer, the processing device to; scan the first set electrodes to measure self-capacitances of the first set of electrodes, using the first dimension multiplexer to route measured signals from the first set of electrodes to receive channels of the processing device, wherein a shield signal is routed through the second dimension multiplexer to the second set of electrodes; identify, based on the measured self-capacitances of the first set of the plurality of electrodes, the presence of an object in proximity to the first set of the plurality of electrodes and the capacitive sense array and not in physical contact with the capacitive sense array; responsive to the identification of the presence of the object based on the measured self-capacitances of the first set of the plurality of electrodes, configure the capacitive sense array to measure a mutual capacitance of at least the first set of electrodes and the second set of electrodes by routing a transmit signal through the first dimension multiplexer to the first set of electrodes and routing measured signals from the second set of electrodes to the receive channels of the processing device; and scan the first set of the plurality of electrodes and the second set of the plurality of electrodes to measure mutual capacitances of intersections between the first set of the plurality of electrodes and the second set of the plurality of electrodes to determine a location of the object. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
-
Specification