Patent ID: 6337626
Filing Date: 2002-01-08
Classification: G08B

Abstract:
A user recognition system for use in a restricted area, said user recognition system having a first alert status which is activated when a legal user or an illegal user enters said restricted area, and a second alert status which is activated when the legal user or illegal user leaves said restricted area, said user recognition system being used with a detector device installed in said restricted area to detect the presence of the user or an illegal user in said restricted area, so as to activate said first alert status or said second alert status, said user recognition system being also used with a guard sensor device to detect an abnormality of said restricted area when in said second alert status, said user recognition system comprising:at least one transmitter each comprising a transmitting circuit for producing a recognition signal and transmitting said recognition signal into the air by radio, and a transmitting control circuit, said transmitting control circuit comprising a code generator for producing a code signal for transmitting with said recognition signal into the air by radio by said transmitting circuit, and a time sequence generator for controlling said transmitting circuit to transmit said recognition signal and said code signal continuously at a predetermined interval; a receiver comprising a microprocessor for processing and controlling the component parts in said receiver, a receiving circuit for receiving and demodulating said recognition signal from said transmitter, a detection interface used with said detector device to detect the presence of the user or the illegal user in said restricted area, enabling said microprocessor to select entry of said first alert status or said second alert status, and a control interface through which said microprocessor sends a control signal to an alarm device connected thereto; wherein when the user recognition system enters said first alert status, said receiver continuously detects the recognition signal from the transmitter carried by the user so as to judge if the legal user is in said restricted area or not, and said microprocessor provides a control signal to drive said alarm device when the legal user is not in said restricted area; and wherein when the user recognition system initiates said second alert status, said receiver does not detect the recognition signal transmitted by said at least one transmitter.