Recessed ceiling mounted passive infrared detector

摘要

A ceiling-mounted passive infrared detector assembly ( 30 ) that has three main components: a junction box ( 10 ) which is adapted to be mounted within an opening in a ceiling; a cover ( 44 ) adapted to mate with the junction box ( 10 ); and an electronic passive infrared detector subassembly ( 43 ) including an infrared sensor ( 42 ) and processing circuitry ( 45 ) for processing electrical signals generated by the infrared sensor ( 42 ) and producing output signals. The cover ( 44 ) has mounting means such as a flange ( 48 ) adapted to mount to the junction box ( 10 ) (or directly to a ceiling if a junction box is not used) and an extended portion ( 50 ) with a cavity ( 52 ) and an aperture ( 46 ). The cover ( 44 ) also has a lens array ( 36 ) located across the aperture ( 46 ). The electronic passive infrared detector subassembly ( 43 ) is located with respect to the cover ( 44 ) such that the infrared sensor ( 42 ) is aligned with the lens array ( 36 ) when the cover ( 44 ) is mounted to the junction box ( 10 ) such that the infrared sensor ( 42 ) detects infrared energy passed through the lens array ( 36 ) from a field of view defined by the juxtaposition of the lens array ( 36 ) and the infrared sensor ( 42 ).