COORDINATE INPUT AND DETECTING DEVICE, AND ELECTRONIC BLACKBOARD SYSTEM

摘要

PROBLEM TO BE SOLVED: To attain improvement in the operability and reliability of a coordinate input and detecting device. SOLUTION: Light receiving and emitting devices 3L and 3R emit light moving forward in an input area 2 while being spread in the shape of a fan, light reflected by a recursive reflecting member 4 for reflecting light emitted from the light receiving and emitting devices 3L and 3R is received, and the intensity distribution of received light is detected. While utilizing the intensity distribution detected by the light receiving and emitting devices 3L and 3R, processing is executed for specifying the position coordinate of an indication object A such as the tip of finger of a user or pen inserted to the input area 2.