Vehicle operator sleep alarm

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. Alternatively, the optical beam of the system may be aimed toward the expected position of the reflector when the driver is awake, and the system is set to emit an alarm only when the reflected beam is no longer received, as when the driver's head nods forward or sideways upon falling asleep. The optical emitter and receiver preferably operate in a portion of the light spectrum beyond human vision, so that the detector system does not interfere with the driver's visual function. The alarm system of the invention may include a self-contained power supply, or may be connected to the vehicle electrical system.