Case 12750

Fluorescent Lamp with Integral Proximity Sensor


Proximity sensor


Energy conservation, lighting, security


Need for energy conservation through lighting control


This invention proposes a proximity sensor that can be integrated with a fluorescent lamp ballast. It measures disturbances in the electric field enabling fine-grain occupancy measurements in spaces without requiring a motion or thermal signature providing a means to improve building energy efficiency through reduction of waste lighting by detection of unoccupied spaces. There are two detection schemes: one uses dimmed sensing to dim the lamp ballasts, the other uses sparse sensing to take advantage of the wide angle of detection of the sensors, requiring fewer lamp sensors. The electronics do not contribute significantly to the noise floor of the lamp sensor. The output sensitivity is affected by electrode spacing, depth and bulb power.


Consistent lighting in occupied spaces with detection of motion and presence for ranges of up to 11 ft.

  • Professor Steven B. Leeb (Department of Electrical Engineering and Computer Science, MIT)
  • Professor Leslie K. Norford (Department of Architecture, MIT)
  • John Jacob Cooley (Department of Electrical Engineering and Computer Science, MIT)
  • Al-Thaddeus Avestruz (Department of Electrical Engineering and Computer Science, MIT)

Intellectual Property:

US Patent Number 7,923,936, issued on April 12, 2011



Last revised: April 29, 2013

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