Abstract: An alarm system for warning a vehicle driver that he or she is falling asleep while driving includes an alarm module mounted in the cabin of the vehicle, preferably above the driver's seat. The module includes an optical beam emitter and receiver directed toward the head of the driver. A reflector is provided to be worn on the head of the driver, either on a hat, cap, headband, or the like. The optical emitter and receiver system is aimed and arranged so that head position associated with loss of wakefulness causes the alarm system to emit a loud warning which wakens the driver immediately. For example, the light beam of the system may be aimed slightly below the expected position of the reflector on the driver's head, so that no light from the optical emitter is reflected to the system receiver when the driver is awake. If the driver begins to doze and the head slumps forward, the reflector is moved into the emitter beam, reflecting light to the optical receiver and setting off the alarm.

Abstract: A system for actuating an alarm and for stopping the engine of a vehicle when the vehicle driver starts to doze or fall asleep. The system includes a mercury switch attachable to the head of the driver, such as on a pair of eyeglasses, and the switch is coupled to a cable having a plug for insertion into the conventional cigarette lighter receptacle on the dashboard of the vehicle. A light flasher, a relay coil, and a buzzer are electrically coupled to the receptacle and energized simultaneously when the mercury switch closes upon movement of the head. The flasher and buzzer provide visual and audible alarms while the relay coil operates a normally closed switch for opening the ignition circuit of the vehicle to stop the engine.