ELECTRONIC DEVICE, ELECTROSTATIC CAPACITANCE SENSOR, AND TOUCH PANEL

摘要

When the excitation frequency of a touch panel and the frequency of external noise match or are close, noise cannot be removed by a bandpass filter. In addition, when a touch detection operating period is limited to a short period such as the no addressing period, the signal-to-noise ratio (S/N) decreases because frequency separation decreases and the noise removal effect by averaging is degraded. An electronic device of the present invention includes a sensor system (101), an excitation generator (102) that generates an intermittent sinusoidal signal and applies this signal to the sensor system, and a demodulator (105) that demodulates the amplitude modulated signal that is the output of the sensor system. The demodulator uses both the response x1(t) of the sensor system in the period in which the excitation generator outputs the sinusoidal signal, and the response z1(t) of the sensor system in the period in which the excitation generator does not output the sinusoidal signal at least either immediately before or immediately after the signal output to generate the demodulated signal D(t).