Importance

Loading Importance Indicators...

Abstract

A motion sensor has a pyroelectric detector, a Fresnel lens array, a reducing lens, and a housing. The detector has two elements located side-by-side and the lens array has a plurality of lenslets which are integrally formed. The reducing lens demagnifies the elements. The reducing lens has grooves which run in parallel directions and face toward the elements. The lens array illuminates the detector by focusing infrared light through the reducing lens and onto the elements. The reducing lens makes the elements appear smaller and closer together. The reduced image of the detector allows the lenslets to be spaced more closely than prior art lenslets, thereby making the angular separation less than the angular separation of prior art sensors. Alternatively, the detector housing may be made smaller while maintaining the same angular separation of prior art sensors. If an object moves between two zones, the sensor detects the movement and triggers an alarm, turns on a light, or initiates some other process.

Loading the Abstract Image...

First Claim