Abstract:
In a method for determining actuation of a first capacitive button having a first set of at least three sensor electrode elements associated with at least three distinct sensor electrodes, and wherein a sensor electrode element of the first set of sensor electrode elements and a sensor electrode element of a second set of at least three sensor electrode elements of a second capacitive button share at least one sensor electrode in common, indicia is received from the at least three distinct sensor electrodes comprising the first capacitive button. At least three electrode values are generated from the indicia. The at least three electrode values are utilized to determine actuation of the capacitive button.
Abstract:
Examples of the present disclosure generally provide current feedback techniques for capacitive sensing with an input device. A processing system for an input device includes an operational amplifier having a non-inverting input, an inverting input, and an output. A voltage source is coupled to the non-inverting input. A first voltage-controlled current source is coupled between the output and the inverting input to form a feedback path. A second voltage-controlled current source is coupled to the output and configured for modifying a charge on a capacitor based on a control voltage at the output. A determination module is coupled to the capacitor and configured for determining a capacitance measurement at the inverting input based on the charge on the capacitor.
Abstract:
Examples of the present disclosure generally relate to a switched capacitance technique for input sensing with an input device. A processing system includes an operational amplifier having a non-inverting input, an inverting input, and an output. The processing system further includes a first capacitor coupled between the output and the inverting input to form a feedback path, and a second capacitor. The processing system further includes a first switch coupled to the second capacitor. The first switch has a first state and a second state, where the first state couples the second capacitor to the first capacitor, and the second state couples the second capacitor to a measurement circuit. The processing system further includes a determination module coupled to the measurement circuit and configured to determine a capacitance measurement at the inverting input based on an amount of charge received by the second capacitor.
Abstract:
A differential amplifier has an output and differential first and second inputs. A switch disposed between a sensor electrode and the second input is opened to initiate a reset phase where the sensor electrode and the differential amplifier are decoupled. A feedback capacitance disposed between the second input and the output is reset to a first level of charge. The switch is closed to initiate a measurement phase where the second input and sensor electrode are coupled. In the measurement phase: charge is balanced between the sensor electrode and the feedback capacitance such that a sensor electrode voltage equals a voltage of the first input equals a voltage of the second input, and the sensor electrode is charged; and the differential amplifier is utilized to integrate charge on the sensor electrode, such that an absolute capacitance corresponding to a coupling between the sensor electrode and an input object is measured.
Abstract:
A system and method for capacitive sensing comprise acquiring first capacitive sensor data and second capacitive sensor data from a plurality of sensor electrodes, and determining positional information from one or more input objects based on the first capacitive sensor data and the second capacitive sensor data. The plurality of sensor electrodes are driven with transcapacitive sensing signals for capacitive sensing during one or more transcapacitive sensing blocks to acquire the first sensor data. Each of the transcapacitive sensing signals is based on a respective one of a plurality of codes. Further, the plurality of sensor electrodes are operated for absolute capacitive sensing during one or more absolute capacitive sensing blocks to acquire the second capacitive sensor data.
Abstract:
Embodiments of the invention generally provide an input device that includes a plurality of sensing elements that are interconnected in desired way to acquire positional information of an input object, so that the acquired positional information can be used by other system components to control a display or other useful system components. One or more of the embodiments described herein, utilizes one or more of the techniques and sensor electrode array configuration disclosed herein to reduce or minimize the number of traces and/or electrodes required to sense the position of an input object within a sensing region of the input device.
Abstract:
A processing system comprises a sensor module and a determination module. The sensor module comprises sensing circuitry coupled to sensor electrodes of a sensor electrode pattern. The sensor module is configured to: drive a modulated signal onto a first sensor electrode of the sensor electrode pattern; receive first resulting signals from the first sensor electrode; and receive second resulting signals from a second sensor electrode of the sensor electrode pattern. The second resulting signals comprise effects corresponding to the modulated signal, and the first resulting signals and the second resulting signals are simultaneously received. The determination module configured to determine a change in capacitive coupling between an input object and the first sensor electrode based on the first resulting signals and a change in capacitive coupling between the first and second sensor electrodes based on the second resulting signals.
Abstract:
A single-layer capacitive sensor comprises a user input region and a border region proximate to and outside of the user input region. The user input region includes a plurality of transmitter electrodes that are disposed within the user input region. The user input region also comprises a plurality of receiver electrodes disposed in a common stackup layer with the plurality of transmitter electrodes within the user input region such that the transmitter electrodes and the receiver electrodes make no crossings of one another in the common stackup layer or in any other layer within the user input region. The border region comprises a plurality of routing traces extending from the border region into the user input region to couple with the transmitter electrodes and the receiver electrodes. The border region also comprises a plurality of transmission traces disposed entirely within the border region.