An EIT Based Large Area Touch Interface

Nowadays, electronic devices are taking over the market and touch panel is a necessary part, among which capacitive touch panel has greater development potential and development space because of its high transparency, multitouch support and low cost. Electrical impedance tomography (EIT) is a technology with the goal of reconstructing tissue image with impedance distribution, which can realize the goal of accurate measurement and maintaining the original characteristics of the medium to the greatest extent at the same time. In this paper, we use EIT-based approach to achieve a large area touch perception imaging system with high light transmittance, which is to obtain the distribution of the permittivity of the touch penal by just detecting the impedance of the electrode scattered around the panel. We use Sensitivity theory to solve the mapping problem between the permittivity distribution and the signal collected by the electrode in the EIT problem. Besides, we innovatively combine LBP with Landweber algorithm to achieve high precision and fast imaging of touch area, which greatly reduces the discomfort caused by inverse problem in EIT method.