Coordinate position inputting/detecting device, a method for inputting/detecting the coordinate position, and a display board system

摘要

In the coordinate-position inputting/detecting device, the light receiving/emitting devices emit light beams spreading in a fan shape and travelling along an entry area. The light receiving/emitting devices also receive the light beam reflected by a recursive reflecting member and detect the distribution of the intensity of the received light beam. The coordinates of a position of a pointing body such as a user's fingertip or a pen inserted in the entry area is identified using the distribution of intensity detected by the light receiving/emitting devices.