COORDINATE DETECTING METHOD, COORDINATE INPUT/DETECTION DEVICE, ELECTRONIC BLACKBOARD SYSTEM AND STORAGE MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide a coordinate input/detection device where the resolution of the detection of a coordinate input position is improved under a constitution using the two groups of light emitting/receiving device groups where a plurality of the light emitting devices and a plurality of light receiving devices are oppositely arranged in two directions crossing to surround a two-dimensional coordinate input/detection area for receiving the insertion of an instruction means. SOLUTION: A plurality of the light receiving devices belonging to light emitting ranges of the respective light emitting devices and detecting light which the light emitting devices emit are allocated in an overlapping manner so that they take charge of a plurality of the light emitting devices (corresponding table 58) and the respective light emitting devices are made to emit light individually and sequentially. Thus, a plurality of radial detection optical paths which are thinner than arranging intervals if viewed from the side of the light emitting devices and the side of the light receiving devices and which are different in the directions can be set. The whole two-dimensional coordinate input/detection area can be covered by the detection optical paths of all directions. Thus, a two-dimensional coordinate position which is specified on the basis of the positional relation of the prescribed light emitting device and the light receiving device where the optical path is interrupted and which is coordinate-inputted can be calculated with high resolution.