Background

Passive infrared (PIR) sensors are used in a variety of applications. They work by using the pyroelectric effect: a change based on the temperature modifies the positions of the atoms. However, because voltage is generated by pyroelectric materials, conventional PIR sensors are unable to detect stationary objects.

Technology

In order to detect stationary objects, new sensors would include a sensing element and a Fresnel lens disposed over a surface of a sensing element. Also included is an optical chopper, thus controlled sensing and control circuitry. The new additions to the sensors will allow stationary objects to be detected.

Advantages

-Able to detect more objects -More accurate sensing with fewer discrepancies

Application

-Detection -Tracking personal identification -Lighting systems -HVAC