An apparatus such as a set-top box, includes at least one capacitive touch button with a guard feature that provides, the ability to detect and reject false touches. According to an exemplary embodiment, the apparatus includes a first conductive element that is capacitively isolated from ground, and a second conductive element that is capacitively isolated from ground and located adjacent to the first conductive element. A first sensor is coupled to the first conductive element and measures a change in capacitance between the first conductive element and ground due to a change in physical environment. A second sensor is coupled to the second conductive element and measures a change in capacitance between the second conductive element and ground due to the change in physical environment. A controller is coupled to the first sensor and the second sensor and determines a difference between the measured changes in capacitance.

There is provided a touch detection circuit including a charging circuit, a discharging circuit, a counter and a processor. The charging circuit charges a detection capacitor within a charging interval using different currents. The discharging circuit discharges the detection capacitor within a discharging interval using different currents. The counter counts the charging interval and the discharging interval. The processor subtracts a baseline time from a counted charging time and a counted discharging time to cancel the noise interference.

An embodiment of the present disclosure relates to a method of detection of a touch contact by a sensor including a first step of comparison of a voltage with a first voltage threshold; and a second step of comparison of the voltage with a second voltage threshold, the second step being implemented if the first voltage threshold has been reached within a duration shorter than a first duration threshold, the second voltage threshold being higher than the first voltage threshold.

The present disclosure provides a touch sensor device that can improve efficiency of acquiring signal components and that can effectively address noise and electromagnetic interference. The touch sensor device includes: a driver unit that drives an electrode having a capacitance that changes due to contact, using a voltage having a waveform of any shape, the voltage gradually changing from a first voltage value that is higher than a reference voltage to a second voltage value that is lower than the reference voltage, and from the second voltage value to the first voltage value; a monitor unit that monitors a drive current obtained by driving the electrode; a rectifying unit that performs full-wave rectification of the current monitored by the monitor unit; and a smoothing unit that smooths the rectified current and converts the rectified current to a current that corresponds to the capacitance of the electrode.

There is provided a detection chip including a charging circuit, a discharging circuit, a counter and a processor. The charging circuit provides a first charging current within a first charging interval, and provides a second charging current, smaller than the first charging current, within a second charging interval. The discharging circuit provides a first discharging current within a first discharging interval, and provides a second discharging current, smaller than the first discharging current, within a second discharging interval. The counter counts the second charging interval and the second discharging interval. The processor identifies a touch event according to the second charging interval and the second discharging interval.

An apparatus, such as a set-top box, includes at least one capacitive touch button with a guard feature that provides, among other things, the ability to detect and reject false touches. According to an exemplary embodiment, the apparatus includes a first conductive element that is capacitively isolated from ground, and a second conductive element that is capacitively isolated from ground and located adjacent to the first conductive element. A first sensor is coupled to the first conductive element and measures a change in capacitance between the first conductive element and ground due to a change in physical environment. A second sensor is coupled to the second conductive element and measures a change in capacitance between the second conductive element and ground due to the change in physical environment. A controller is coupled to the first sensor and the second sensor and determines a difference between the measured changes in capacitance of the first sensor and the second sensor.

A device for measuring a variation (ΔC.sub.X) of a capacitance (C.sub.X), includes: elements for charging the capacitance (C.sub.X) on the basis of a supply voltage (V.sub.CC). elements for discharging the capacitance (C.sub.X) into a reference capacitance (C.sub.S) in a fixed number of discharges (x), elements for measuring a voltage (V.sub.S) and for detecting a threshold of voltage (V.sub.TH) across the terminals of the reference capacitance (C.sub.S). elements for charging with current (I.sub.C) the reference capacitance (C.sub.S) on the basis of the supply voltage (V.sub.CC) for a duration (t), after the transfer of charge from the capacitance (C.sub.X) into the reference capacitance (C.sub.S), and elements for measuring the variation between the duration (t) with respect to a previously measured duration so as to estimate the variation (ΔC.sub.X) of the capacitance (C.sub.X).

A touch controller for an LED light string or light strip is disclosed. The touch controller includes a housing, an end cover connected with the housing, a liquid-sealed accommodating cavity being defined between the end cover and the housing, a printed circuit board positioned in the accommodating cavity, a light-emitting control circuit being arranged on the printed circuit board, a touch input unit positioned in the accommodating cavity, the touch input unit being electrically connected with the light-emitting control circuit, one part of the touch input unit being matched with the housing or the end cover, and when a touch behavior is applied to the part, matched with the touch input unit, of the housing or the end cover, a trigger signal is provided for the light-emitting control circuit through the touch input unit.

There is provided a touch detection circuit including a charging circuit, a discharging circuit, a counter and a processor. The charging circuit charges a detection capacitor within a charging interval using different currents. The discharging circuit discharges the detection capacitor within a discharging interval using different currents. The counter counts the charging interval and the discharging interval. The processor subtracts a baseline time from a counted charging time and a counted discharging time to cancel the noise interference.

The present disclosure discloses a position detection system, which comprising a power module, a detection module, a control module, and a pulse module. The power module is configured to supply power. The detection module comprises a key detection circuit and a force detection circuit. The control module is electrically connected to the power module and the detection module, and configured to process the key detection data detected by the key detection circuit and the force detection data detected by the force detection circuit and output a key signal and a force signal. The pulse module is connected to the control module, and configured to acquire start references of the key signal and the force signal output by the control module, and convert the key signal and the force signal to digital signals by form coding and send the digital signals to a tablet. The present discloses further provides a digital stylus using the same.