Position detecting device

摘要

An object of the present invention is to provide a position detecting device that allows simultaneous use by a plurality of users by recognizing positional information about a plurality of pointers and associating the pointers and the users. A position detecting device of the invention includes a rear projector (1) that projects an image, a projection screen (3) that displays the image projected from the rear projector (1), imaging means (4) that is located near the rear projector (1) and that takes an image of light rays emitted from pointers (10, 20), from the rear of the projection screen (3), and coordinate calculating means (5b) that analyzes the image taken by the imaging means (4) to detect the two-dimensional positions in the detection areas where the light rays from the pointers (10, 20) are detected.