Double fresnel pir lens

摘要

A sensor module for a lighting fixture includes a module housing configured to be mounted to a lighting fixture, a light sensor mounted in the module housing, and a sensor cover over the light sensor. The sensor cover includes a first surface oriented to face a task surface within an area of interest, and a second surface opposite the first surface. The first surface includes a first Fresnel lens having a number of Fresnel ridges oriented in a first direction. The second surface includes a second Fresnel lens having a number of Fresnel ridges oriented in a second direction, which is different from the first direction. Providing the first Fresnel lens and the second Fresnel lens with differently oriented Fresnel ridges allows the sensor cover to focus light from a relatively large portion of the task surface to the light sensor while remaining small.