A Pen-Pressure-Sensitive Capacitive Touch System Using Electrically Coupled Resonance Pen

作者:Park Changbyung*; Park Sungsoo; Kim Ki Duk; Park Sanghui; Park Juwan; Kang Byunghoon; Huh Yunhee; Cho Gyu Hyeong
来源:IEEE Journal of Solid-State Circuits, 2016, 51(1): 168-176.
DOI:10.1109/JSSC.2015.2453943

摘要

A touch system sensing pen-pressure of the proposed electrically coupled resonance (ECR) pen is implemented, which can replace costly digitizer system containing electro magnetic resonance (EMR) and capacitive touch system. The proposed system detects the location of the ECR pen and finger using proposed position sensor, and senses pen-pressure of ECR pen using proposed pen-pressure sensor. For the position sensor, to detect even small variation of the mutual capacitance on touch screen panel (TSP) of the pen, a simultaneous driving scheme is proposed with modified Hadamard matrix, resulting in highly increased dynamic range and SNR. In the proposed pen-pressure sensor, the resonant frequency of the ECR pen is measured by a frequency to voltage converter based sensor. The measured SNR for the pen position is 49 dB with 1 mm phi metal pillar, and 6.5-bit resolution is achieved for pen-pressure sensor in 6 sigma criteria.

  • 出版日期2016-1