Off side detection system for use by referee or assistant in game of soccer

摘要

The system is comprised of a portable emitter which is activated by the referee by mechanical pulsing which will always be effected when the player who has the ball passes the ball to another player. The system also comprises a portable receiver which is carried by the assistant; said receiver has a button and can be activated by the assistant by pulsing it whenever a player is in an off side position. The system provides a signal which is perceived by a person in order to indicate to this person that the ball has been passed by one player while another player was off side.