SYSTEM FOR DETECTING THE PRESENCE AND LOCATION OF AT LEAST ONE OBJECT IN A FIELD BY USING A DIVERGENT RADIATION SOURCE AND AN ARRAY OF OPPOSED PLURAL DETECTORS WHICH ROTATE TOGETHER AROUND THE FIELD

摘要

An apparatus detects the presence and location of at least one object in a field. The apparatus comprises a rotating arm (44) which spins around the field, a position sensor (48) for detecting the angular displacement of the rotating arm (44) relative to a fixed point, and a processor (U9). The rotating arm (44) includes a transmitter (64) and an opposing receiver array (72) mounted thereon and fixed relative to each other. The receiver array (72) includes a plurality of receivers (68) located horizontally coplanar with each other. The receivers (68) are concentrated towards one side of the receiver array (72) which is aligned with a center region of the dartboard. The transmitter (64) outputs a detection beam (76) that emanates from a single point, such as a divergent beam. The detection beam (76) overlaps the field and is simultaneously received at all times by the plurality of receivers (68) of the receiver array (72). The receivers (68) detect changes which occur in the field as a result of an object being in the field, manifested by shadows on the field. The processor (U9) receives output signals from the plurality of receivers (68) and angular displacement data corresponding to the output signals, and determines therefrom the presence and location of an object in the field. The field may be a dartboard (14) front surface and the detected object in the field may be a dart (12) which lands on the dartboard (14) front surface. The dartboard (14) may be a Bandit® dartboard. The dartboard (14) may be mounted in a housing (30) wherein the front of the housing (30) includes an outer catch ring area (33) having a plurality of removably attachable catch ring segments (34) made of dart-permeable and dart catching material. The processor (U9) detects when a player's turn is over by detecting removal of the darts (12) from the dartboard (14) and automatically advances a scoring display (38) to the next player.