A Highly Linear and Accurate Fork-Shaped Electrode Pattern for Large-Sized Capacitive Touch Screen Panels

Abstract

This paper proposes a fork-shaped electrode (FSE) pattern that has high linearity and high spatial accuracy of the extracted touch coordinates for large-sized touch screen panels (TSPs). The proposed FSE pattern has a large variation in mutual capacitance ( $\Delta \text{C}_{\mathbf {M}}$ ) and shows similar $\Delta \text{C}_{\mathbf {M}}$ distributions in various touch directions, thus improving the linearity and spatial accuracy of the extracted touch coordinates. The performances of the proposed FSE pattern were verified by carrying out both simulation and measurement using a 32-inch capacitive TSP with a 12 mm electrode pitch, and compared with those of the conventional Manhattan- and diamond-shaped electrode patterns. The measurement results show that the linearity and spatial accuracy of the extracted touch coordinates are improved by more than 14.40% and 9.64%, respectively, when compared with those achieved in the conventional electrode patterns.