At least one exemplary embodiment is directed detecting a position pointed on a coordinate input region by using a first and second sensor units provided in the vicinities of both ends of one side of a coordinate input region, angle information representing directions of shadows, which are areas light-shielded...http://www.google.de/patents/US20060232830?utm_source=gb-gplus-sharePatent US20060232830 - Coordinate input apparatus, control method therefore, and program
