Reflectors in a scene are reconstructed using reflected signals. The first to fourth conductive magnetic films, each extending parallel to a tip face of a magnetic head to be opposed to a magnetic recording medium, are aligned at a distance from one another in a direction perpendicular to the tip face so as to be away from the tip face in ascending order and connected to one another so as to form a bridge circuit. ATNs are created that directly model complex pattern continuous queries with arbitrary cycles in a transition graph. As a result a secret message can be sent from the sender to the receiver without being eavesdropped on during the communication. An output control circuit is connected to the parallel to serial conversion circuit via the first through nth paths, the output control circuit successively outputting the first through nth data in the first operating mode, and outputting only the th data supplied from the parallel to serial conversion circuit in the second operating mode. An outer ring gear surrounds all of the lug gears providing an inward pressure that maintains the connection between the teeth of the lug gears and the central gear.