Different technology. This is what we've used: http://www.touchscreen-me.com/technologies-comparison-infrared.php http://www.touchscreen-me.com/technologies-com

Different technology. This is what we've used: http://www.touchscreen-me.com/technologies-comparison-infrared.php http://www.touchscreen-me.com/technologies-comparison-infrar... Same result can be achieved with CMOS sensors mounted on the corners as well but ambient lighting conditions affect the way the board works.