FLATIR: FTIR Multi-touch Detection on a Discrete Distributed Sensor Array

Proceedings of the Third International Conference on Tangible and Embedded Interaction (TEI'09), Feb 16-18 2009, Cambridge, UK. - 6 p.In this paper, we suggest a new way to add multi-touch capabilities to an LC-screen. For this, FTIR and IR-sensing behind the LC-screen will be combined. Using a large infrared sensor array mounted behind the LC-matrix, infrared light in front of the screen, which is strong enough to pass through the LC-screen’s components, can be detected The FTIR-technology is able to deliver such infrared light to the integrated sensors when touching the screen with the fingers. For the prototype, the key parameters of the FTIR principle were experimentally analyzed to optimize the sensor reactivity. The 4x8 sensor prototype can simultaneously detect multiple touches with an accuracy of around 1 mm and with an update rate of 200 Hz.