A Study on a Lattice Resistance Mesh Model of Display Cathode Electrodes for Capacitive Touch Screen Panel Sensors

摘要

As the display panels with embedded touch sensors get thinner for slim and compact devices, the impact of display noise flowing into touch screen panels has become problematic. Although the display noise has been regarded as a common-mode noise for touch sensors, it can show a noticeable spatial variation in case of extremely thin modules like flexible display modules. To deal with the non-uniform property of the display noise, we examined the resistance distribution of a display cathode electrode that the display noise is passing through, and proposed a cross-type lattice resistance mesh circuit model to correctly reflect resistance around a trace-to-cathode contact region. Using the proposed model, we could accurately predict a local variation of display noises with 5% maximum error.