Coordinate detection device and coordinate detection method

Abstract

[Problem] To detect touch coordinates, without detection errors and without using a special pen, on a substrate such as a touch panel. [Solution] This coordinate detection method comprises: calculating a ratio between the short-term average (STA) and long-term average (LTA) of output signals from at least three vibration detectors installed apart from each other at predetermined distances on a substrate which has a uniform thickness and is made from a homogeneous material that allows the propagation speeds of oscillating waves to be constant; calculating, as arrival times, the times at which the STA/LTA ratio of the three vibration detectors by oscillating waves generated by touching the substrate exceeds a predetermined threshold value; and calculating touch position coordinates on the basis of each of the arrival times, the propagation speed of the oscillating waves, and the distances at which the three vibration detectors are spaced apart from each other.