Capacitive position encoder
First Claim
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1. A device comprising:
- a substrate;
a drive electrode disposed on a first side of the substrate;
a plurality of sense electrodes disposed on a second side of the substrate;
a wiper comprising at least one arm, the wiper electrically insulated from the plurality of sense electrodes, the wiper coupled to a ground of the device; and
a controller coupled to the drive electrode and the plurality of sense electrodes, the controller comprising;
a drive unit configured to generate at least one drive signal and drive the drive electrode with the at least one drive signal;
a sense unit configured to detect, for each sense electrode of the plurality of sense electrodes, a charge stored by the sense electrode; and
a processor unit operable to determine a position of the wiper relative to the plurality of sense electrodes, the determination based on the plurality of charges detected by the sense unit.
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Abstract
In one embodiment, a method comprises driving one or more drive electrodes formed on a substrate with one or more drive signals. A wiper comprising at least one arm is driven to a predetermined voltage. The wiper is electrically insulated from a plurality of sense electrodes formed on the substrate. For each sense electrode of the plurality of sense electrodes, a charge stored by the sense electrode is detected. A processor determines a position of the wiper based on the detected charges stored by the plurality of sense electrodes.
20 Citations
20 Claims
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1. A device comprising:
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a substrate; a drive electrode disposed on a first side of the substrate; a plurality of sense electrodes disposed on a second side of the substrate; a wiper comprising at least one arm, the wiper electrically insulated from the plurality of sense electrodes, the wiper coupled to a ground of the device; and a controller coupled to the drive electrode and the plurality of sense electrodes, the controller comprising; a drive unit configured to generate at least one drive signal and drive the drive electrode with the at least one drive signal; a sense unit configured to detect, for each sense electrode of the plurality of sense electrodes, a charge stored by the sense electrode; and a processor unit operable to determine a position of the wiper relative to the plurality of sense electrodes, the determination based on the plurality of charges detected by the sense unit. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method comprising:
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driving one or more drive electrodes former on a substrate with one or more drive signals; driving a wiper comprising at least one arm to a predetermined voltage, the wiper electrically insulated from a plurality of sense electrodes formed on the substrate; detecting, for each sense electrode of the plurality of sense electrodes, a charge stored by the sense electrode; and determining, by a processor, a position of the wiper based on the detected charges stored by the plurality of sense electrodes. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. An apparatus comprising:
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at least one drive electrode disposed on a substrate; a plurality of sense electrodes disposed on the substrate; a wiper comprising at least one arm, the wiper electrically insulated from the plurality of sense electrodes; and a controller operable to; drive the at least one drive electrode; detect a plurality of charges stored by the plurality of sense electrodes; and determine a position of the wiper based on the plurality of charges detected by the sense unit. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification