Abstract: A touch sensor system includes a sensing area having a periphery and a plurality of light sources and a plurality of analog optical detectors arranged about the periphery of the sensing area. The system further includes addressing circuitry that selectively drives each of the plurality of light sources with a modulated signal and selectively activates the plurality of analog optical detectors, and a controller that receives a collective detector output from the plurality of analog optical detectors. The outputs from the analog optical detectors may be a time multiplexed to provide the collective detector output. Each optical detector may include a photodiode; a first transistor coupled to the photodiode in a current amplifier configuration that generates an amplified current output as a function of a photodiode current; and enable circuitry to enable and disable the optical detector as a function of an enable input signal.

Abstract: A touch sensor system includes a sensing area having a periphery and a plurality of light sources and a plurality of analog optical detectors arranged about the periphery of the sensing area. The system further includes addressing circuitry that selectively drives each of the plurality of light sources with a modulated signal and selectively activates the plurality of analog optical detectors, and a controller that receives a collective detector output from the plurality of analog optical detectors. The outputs from the analog optical detectors may be a time multiplexed to provide the collective detector output. Each optical detector may include a photodiode; a first transistor coupled to the photodiode in a current amplifier configuration that generates an amplified current output as a function of a photodiode current; and enable circuitry to enable and disable the optical detector as a function of an enable input signal.

Abstract: In a frequency multiplexed capacitive touch sensor, a plurality of resonance frequencies may be used to drive electrodes for sensing touch. A capacitive touch sensor apparatus is provided that includes a substrate layer and a plurality of resonant circuits. Each resonant circuit comprises a respective electrode and a respective electromechanical resonator connected to the respective electrode. The electromechanical resonators comprise any suitable high-Q resonator including, but not limited to: ceramic oscillators; crystal oscillators; and MEMs oscillators, as described above. The electrodes of the plurality of resonant circuits are distributed on the substrate layer. The electromechanical resonators may allow relatively close spacing of adjacent resonance frequencies, in comparison to resonant circuits with discrete inductors.

Abstract: A capacitive touch sensor comprises a plurality of electrodes on a substrate, and a position of a finger touching the sensor is determined by monitoring output signal changes caused by changes in capacitance caused by the present of the finger over or near the electrodes. The disclosure provides a capacitive touch sensor apparatus comprising a substrate and a plurality of touch sensor electrodes arranged on the substrate. Each of the electrodes comprises a respective primary electrode strip and a respective one or more electrode strip branches extending from the primary electrode strip.

Abstract: The disclosure provides methods and apparatuses for detecting two-touch events with a five-wire resistive touch sensor comprising an active layer and a sensing layer. The methods include, while a first voltage gradient is generated across an active layer of the sensor, measuring a first voltage of a sensing layer electrode and a current across the sensor. The methods further include, while the second voltage gradient is generated across the active layer, measuring a second voltage of the sensing layer electrode and a second current across the sensor. The first and second currents are compared to a respective threshold. A two-touch event is detected based on the comparison.

Abstract: In a frequency multiplexed capacitive touch sensor, a plurality of resonance frequencies may be used to drive electrodes for sensing touch. A capacitive touch sensor apparatus is provided that includes a substrate layer and a plurality of resonant circuits. Each resonant circuit comprises a respective electrode and a respective electromechanical resonator connected to the respective electrode. The electromechanical resonators comprise any suitable high-Q resonator including, but not limited to: ceramic oscillators; crystal oscillators; and MEMs oscillators, as described above. The electrodes of the plurality of resonant circuits are distributed on the substrate layer. The electromechanical resonators may allow relatively close spacing of adjacent resonance frequencies, in comparison to resonant circuits with discrete inductors.

Abstract: A capacitive touch sensor comprises a plurality of electrodes on a substrate, and a position of a finger touching the sensor is determined by monitoring output signal changes caused by changes in capacitance caused by the present of the finger over or near the electrodes. The disclosure provides a capacitive touch sensor apparatus comprising a substrate and a plurality of touch sensor electrodes arranged on the substrate. Each of the electrodes comprises a respective primary electrode strip and a respective one or more electrode strip branches extending from the primary electrode strip.

Abstract: A common capacitive touch sensor may have a two dimensional array of transparent conductive strips going from edge to edge on a substrate layer or sheet of a touch sensor. According to some aspects, there is provided a capacitive touch sensor device including a substrate layer and a plurality of resonant circuits. Each resonant circuit includes an electrode, and each resonant circuit has a respective resonance frequency that is unique within the plurality of resonant circuits. The electrodes of the resonant circuits are distributed on the substrate layer. A controller for a touch sensor is also provided that includes a signal generator to drive at least one plurality of resonant circuits, where each resonant circuit has a respective resonance frequency. The signal generator is tunable to generate input signals at each of the resonance frequencies. The controller also includes a detector.

Abstract: The disclosure provides methods and apparatuses for detecting two-touch events with a five-wire resistive touch sensor comprising an active layer and a sensing layer. The methods include, while a first voltage gradient is generated across an active layer of the sensor, measuring a first voltage of a sensing layer electrode and a current across the sensor. The methods further include, while the second voltage gradient is generated across the active layer, measuring a second voltage of the sensing layer electrode and a second current across the sensor. The first and second currents are compared to a respective threshold. A two-touch event is detected based on the comparison.

Abstract: A common capacitive touch sensor may have a two dimensional array of transparent conductive strips going from edge to edge on a substrate layer or sheet of a touch sensor. According to some aspects, there is provided a capacitive touch sensor device including a substrate layer and a plurality of resonant circuits. Each resonant circuit includes an electrode, and each resonant circuit has a respective resonance frequency that is unique within the plurality of resonant circuits. The electrodes of the resonant circuits are distributed on the substrate layer. A controller for a touch sensor is also provided that includes a signal generator to drive at least one plurality of resonant circuits, where each resonant circuit has a respective resonance frequency. The signal generator is tunable to generate input signals at each of the resonance frequencies. The controller also includes a detector.

Abstract: A common capacitive touch sensor may have a two dimensional array of transparent conductive strips going from edge to edge on a substrate layer or sheet of a touch sensor. According to some aspects, there is provided a capacitive touch sensor device including a substrate layer and a plurality of resonant circuits. Each resonant circuit includes an electrode, and each resonant circuit has a respective resonance frequency that is unique within the plurality of resonant circuits. The electrodes of the resonant circuits are distributed on the substrate layer. A controller for a touch sensor is also provided that includes a signal generator to drive at least one plurality of resonant circuits, where each resonant circuit has a respective resonance frequency. The signal generator is tunable to generate input signals at each of the resonance frequencies. The controller also includes a detector.