System and method for background noise measurement and frequency selection in touch panel sensor

• Main Authors: ERDOGAN OZAN E, SHEN GUOZHONG, KNOX KENNETH W, MAHMUD SYED
• Format: Patent
• Language: Chinese; English
• Published: 19.09.2012
• Subjects: CALCULATING; COMPUTING; COUNTING; ELECTRIC DIGITAL DATA PROCESSING; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

The invention relates to a system and a method for background noise measurement and frequency selection in touch panel sensor. A touch panel sensor system that can dynamically measure noise and automatically switch to a frequency with minimal noise is described. The touch panel sensor system includes a sensor configured to detect a change in capacitance associated with a touch upon a touch panel. The system also includes a drive module configured to generate a drive signal having a first waveform characteristic (e.g., signal having a periodic waveform characteristic) during a first phase (e.g., sensor phase) and a second drive signal having a second waveform characteristic (e.g., constant voltage signal) during a second phase (e.g., noise detection phase). The first and second drive signals are configured to drive the sensor. The system also includes a measuring module coupled to the sensor that is configured to measure noise having the first waveform characteristic (e.g., periodic waveform characteristic) du