Design of a Touch Controller for Multitouch Screen System With Touch Prediction and Window Sensing (TPWS) Strategy

作者：Wei, Xiaomin^*; Li, Bo; Wei, Tingcun; Wang, Jia; Zheng, Ran

来源：Journal of Display Technology, 2016, 12(12): 1638-1646.

DOI：10.1109/JDT.2016.2612698

• Differential measurement
• multitouch screen system
• touch controller
• touch prediction and window sensing (TPWS)

The touch prediction and window sensing (TPWS) strategy is an effective approach to realize low-cost and low-power multitouch screen systems, especially for large-sized touch screen panels. The structures of traditional touch controller using charge integrating amplifier is not suitable for the TPWS touch screen systems. This paper presents a new touch controller, which is designed for the TPWS touch screen systems and is emphasized to improve the SNR and reporting rate of system. The differential measurement scheme with a full driving method is proposed to eliminate the influences on the SNR and the reporting rate of system caused by the LCD noise, the charger noise and the signal transmission delay on Indium-Tin Oxide (ITO) electrodes. The designed touch controller is realized in a 0.13 mu m1.8 V/5 V embedded flash CMOS process with the chip size of 2.5x2.8mm(2). The test results demonstrate that this touch controller supports the TPWS strategy very well and its performances are improved significantly. Comparing with the previous design, the SNR is improved from 25 to 36 dB, and the reporting rate is increased from 83 to 120 Hz.

• 出版日期2016-12
• 单位西北工业大学