摘要:
A front-end signal detector and a method for improving noise immunity of a capacitive touch sensor start counting a preset time to trigger an interrupt signal responsive to a positive or negative edge of a periodic noise, to break the path through which a demodulated signal comes into a low-pass filter, to prevent noise from accumulating in the low-pass filter, and consequently mitigate the influence of the noise on the detection signal generated by the front-end signal detector.
摘要:
A front-end signal detector and a method for improving noise immunity of a capacitive touch sensor start counting a preset time to trigger an interrupt signal responsive to a positive or negative edge of a periodic noise, to break the path through which a demodulated signal comes into a low-pass filter, to prevent noise from accumulating in the low-pass filter, and consequently mitigate the influence of the noise on the detection signal generated by the front-end signal detector.
摘要:
A sensing method and circuit for a capacitive touch panel sense the capacitance variation of a lateral capacitor formed at the intersection of two traces of the capacitive touch panel, to distinguish a real point from a ghost point. A sensing cycle includes two non-overlapping clock phases. In the first clock phase, the voltages across the lateral capacitor and across a sensing capacitor are set. In the second clock phase, the voltage at a first terminal of the lateral capacitor is changed, and a second terminal of the lateral capacitor is connected to a first terminal of the sensing capacitor, causing a voltage variation at a second terminal of the sensing capacitor. This voltage variation is used to determine whether the intersection is touched. The sensing method and circuit reflect the status of the lateral capacitor in real-time and prevent the location of the touch point from being misjudged.
摘要:
An electronic stylus emits an excitation signal to apply to a trace of a capacitive touchpad module near a touch point when the electronic stylus touches the capacitive touchpad module, so as to change a waveform of a charging/discharging signal in the trace, and depending on the waveform variation, the capacitive touchpad module can identify the touch point.
摘要:
A touch position detector includes a plurality of capacitance sensors, a negative capacitance compensation unit, an analog/digital converter and a micro processing unit. The negative capacitance compensation unit is utilized to compensate the capacitance of the capacitance sensor and get a capacitance change. The micro controller unit is utilized to detect the touch position according to the capacitance change. It is easy to get the touch position by using the touch position detector.
摘要:
A control circuit and a control method for a capacitive touch panel are provided. Therein, while a scanning signal charges and discharges each trace on the capacitive touch panel, a signal in phase with the scanning signal is provided to traces adjacent to the scanned trace or a ground layer under the scanned trace so as to lower parasitic capacitances between the scanned trace and the ground layer or other traces, thereby decreasing a base capacitance of the capacitive touch panel and enhancing a sensing result of the control circuit as well as providing a shielding effect and reducing noise interference so that the capacitive touch panel has improved performance.
摘要:
An equalized capacitive touchpad and a touch positioning method for a capacitive touchpad use an equalizer to correct a sensed value detected from a sensing line of the capacitive touchpad, to thereby offset the attenuation of the sensed value due to the impedance of the sensing line. Thus, the sensed values generated from different positions along a sensing line are equalized, and the touch positioning accuracy of the capacitive touchpad is improved.
摘要:
A touch position detector includes a plurality of capacitance sensors, a negative capacitance compensation unit, an analog/digital converter and a micro processing unit. The negative capacitance compensation unit is utilized to compensate the capacitance of the capacitance sensor and get a capacitance change. The micro controller unit is utilized to detect the touch position according to the capacitance change. It is easy to get the touch position by using the touch position detector.
摘要:
An equalized capacitive touchpad and a touch positioning method for a capacitive touchpad use an equalizer to correct a sensed value detected from a sensing line of the capacitive touchpad, to thereby offset the attenuation of the sensed value due to the impedance of the sensing line. Thus, the sensed values generated from different positions along a sensing line are equalized, and the touch positioning accuracy of the capacitive touchpad is improved.
摘要:
An object location sensor of a touch panel has at least one capacitive sensing set having two adjacent capacitive sensors. The at least one capacitive sensing set is arranged along a direction, one capacitive sensor has a capacitance value increasing gradually along the direction, and another capacitive sensor has a capacitance value decreasing gradually along the direction.